1
|
Murray BE, Penabad LI, Kennedy RT. Advances in coupling droplet microfluidics to mass spectrometry. Curr Opin Biotechnol 2023; 82:102962. [PMID: 37336080 DOI: 10.1016/j.copbio.2023.102962] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Revised: 05/12/2023] [Accepted: 05/23/2023] [Indexed: 06/21/2023]
Abstract
Droplet microfluidics enables development of workflows with low sample consumption and high throughput. Fluorescence-based assays are most used with droplet microfluidics; however, the requirement of a fluorescent reporter restricts applicability of this approach. The coupling of droplets to mass spectrometry (MS) has enabled selective assays on complex mixtures to broaden the analyte scope. Droplet microfluidics has been interfaced to MS via electrospray ionization (ESI) and matrix-assisted laser desorption ionization (MALDI). The works reviewed herein outline the development of this nascent field as well as initial exploration of its application in biotechnology and bioanalysis, including synthetic biology, reaction development, and in vivo sensing.
Collapse
Affiliation(s)
- Bridget E Murray
- Department of Chemistry, University of Michigan, 930 N. University Ave, Ann Arbor, MI 48109-1055, USA
| | - Laura I Penabad
- Department of Chemistry, University of Michigan, 930 N. University Ave, Ann Arbor, MI 48109-1055, USA
| | - Robert T Kennedy
- Department of Chemistry, University of Michigan, 930 N. University Ave, Ann Arbor, MI 48109-1055, USA.
| |
Collapse
|
2
|
Luo Y, Huang Y, Li Y, Duan X, Jiang Y, Wang C, Fang J, Xi L, Nguyen NT, Song C. Dispersive phase microscopy incorporated with droplet-based microfluidics for biofactory-on-a-chip. LAB ON A CHIP 2023. [PMID: 37194324 DOI: 10.1039/d3lc00127j] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Biomolecular imaging of intracellular structures of a single cell and subsequent screening of the cells are of high demand in metabolic engineering to develop strains with the desired phenotype. However, the capability of current methods is limited to population-scale identification of cell phenotyping. To address this challenge, we propose to utilize dispersive phase microscopy incorporated with a droplet-based microfluidic system that combines droplet volume-on-demand generation, biomolecular imaging, and droplet-on-demand sorting, to achieve high-throughput screening of cells with an identified phenotype. Particularly, cells are encapsulated in homogeneous environments with microfluidic droplet formation, and the biomolecule-induced dispersive phase can be investigated to indicate the biomass of a specific metabolite in a single cell. The retrieved biomass information consequently guides the on-chip droplet sorting unit to screen cells with the desired phenotype. To demonstrate the proof of concept, we showcase the method by promoting the evolution of the Haematococcus lacustris strain toward a high production of natural antioxidant astaxanthin. The validation of the proposed system with on-chip single-cell imaging and droplet manipulation functionalities reveals the high-throughput single-cell phenotyping and selection potential that applies to many other biofactory scenarios, such as biofuel production, critical quality attribute control in cell therapy, etc.
Collapse
Affiliation(s)
- Yingdong Luo
- A School of Mechanical Engineering and Electronic Information, China University of Geosciences, Wuhan, 430074, China.
| | - Yuanyuan Huang
- A School of Mechanical Engineering and Electronic Information, China University of Geosciences, Wuhan, 430074, China.
| | - Yani Li
- A School of Mechanical Engineering and Electronic Information, China University of Geosciences, Wuhan, 430074, China.
| | - Xiudong Duan
- A School of Mechanical Engineering and Electronic Information, China University of Geosciences, Wuhan, 430074, China.
| | - Yongguang Jiang
- School of Environmental Studies, China University of Geosciences, Wuhan 430074, China
| | - Cong Wang
- A School of Mechanical Engineering and Electronic Information, China University of Geosciences, Wuhan, 430074, China.
| | - Jiakun Fang
- State Key Laboratory of Advanced Electromagnetic Engineering and Technology, School of Electrical and Electronic Engineering, Huazhong University of Science and Technology, Wuhan, China.
| | - Lei Xi
- Department of Biomedical Engineering, Southern University of Science and Technology, Shenzhen, China.
| | - Nam-Trung Nguyen
- Queensland Micro, and Nanotechnology Centre, Griffith University, 170 Kessels Road, QLD 4111, Nathan, Australia
| | - Chaolong Song
- A School of Mechanical Engineering and Electronic Information, China University of Geosciences, Wuhan, 430074, China.
| |
Collapse
|
3
|
Jiang Z, Shi H, Tang X, Qin J. Recent advances in droplet microfluidics for single-cell analysis. Trends Analyt Chem 2023. [DOI: 10.1016/j.trac.2023.116932] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
|
4
|
Cruz Villarreal J, Kruithoff R, Egatz-Gomez A, Coleman PD, Ros R, Sandrin TR, Ros A. MIMAS: microfluidic platform in tandem with MALDI mass spectrometry for protein quantification from small cell ensembles. Anal Bioanal Chem 2022; 414:3945-3958. [PMID: 35385983 PMCID: PMC9188328 DOI: 10.1007/s00216-022-04038-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Revised: 03/17/2022] [Accepted: 03/22/2022] [Indexed: 11/26/2022]
Abstract
Understanding cell-to-cell variation at the molecular level provides relevant information about biological phenomena and is critical for clinical and biological research. Proteins carry important information not available from single-cell genomics and transcriptomics studies; however, due to the minute amount of proteins in single cells and the complexity of the proteome, quantitative protein analysis at the single-cell level remains challenging. Here, we report an integrated microfluidic platform in tandem with matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS) for the detection and quantification of targeted proteins from small cell ensembles (> 10 cells). All necessary steps for the assay are integrated on-chip including cell lysis, protein immunocapture, tryptic digestion, and co-crystallization with the matrix solution for MALDI-MS analysis. We demonstrate that our approach is suitable for protein quantification by assessing the apoptotic protein Bcl-2 released from MCF-7 breast cancer cells, ranging from 26 to 223 cells lysed on-chip (8.75 nL wells). A limit of detection (LOD) of 11.22 nM was determined, equivalent to 5.91 × 107 protein molecules per well. Additionally, the microfluidic platform design was further improved, establishing the successful quantification of Bcl-2 protein from MCF-7 cell ensembles ranging from 8 to 19 cells in 4 nL wells. The LOD in the smaller well designs for Bcl-2 resulted in 14.85 nM, equivalent to 3.57 × 107 protein molecules per well. This work shows the capability of our approach to quantitatively assess proteins from cell lysate on the MIMAS platform for the first time. These results demonstrate our approach constitutes a promising tool for quantitative targeted protein analysis from small cell ensembles down to single cells, with the capability for multiplexing through parallelization and automation.
Collapse
Affiliation(s)
- Jorvani Cruz Villarreal
- School of Molecular Sciences, Arizona State University, Temple, AZ, USA
- Center for Applied Structural Discovery, The Biodesign Institute, Arizona State University, Tempe, AZ, USA
| | - Rory Kruithoff
- Department of Physics and Center for Biological Physics, Arizona State University, Tempe, AZ, USA
| | - Ana Egatz-Gomez
- School of Molecular Sciences, Arizona State University, Temple, AZ, USA
- Center for Applied Structural Discovery, The Biodesign Institute, Arizona State University, Tempe, AZ, USA
| | - Paul D Coleman
- School of Life Sciences, Arizona State University, Temple, AZ, USA
- ASU-Banner Neurodegenerative Research Center, The Biodesign Institute, Arizona State University, Tempe, AZ, USA
| | - Robert Ros
- Department of Physics and Center for Biological Physics, Arizona State University, Tempe, AZ, USA
- Center for Single Molecule Biophysics, The Biodesign Institute, Arizona State University, Temple, AZ, USA
| | - Todd R Sandrin
- School of Mathematical and Natural Sciences, Arizona State University, Phoenix, AZ, USA
- Julie Ann Wrigley Global Futures Laboratory, Arizona State University, Tempe, AZ, USA
| | - Alexandra Ros
- School of Molecular Sciences, Arizona State University, Temple, AZ, USA.
- Center for Applied Structural Discovery, The Biodesign Institute, Arizona State University, Tempe, AZ, USA.
| |
Collapse
|
5
|
Wang M, Liao X, Tchounwou PB, Liu YM. Coupling a droplet generator with conventional ESI-MS for quantitative analysis of small-volume samples. Anal Bioanal Chem 2022; 414:1809-1817. [PMID: 35061061 PMCID: PMC8828272 DOI: 10.1007/s00216-021-03808-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2021] [Revised: 11/22/2021] [Accepted: 11/25/2021] [Indexed: 02/03/2023]
Abstract
Quantitative mass spectrometric analysis of small-volume samples (e.g., < 1 μL) has been a challenge mainly due to the difficulties with sample handling and its injection into the system for analysis. Herein we report a microfluidic analytical platform coupling a droplet generator with conventional electrospray ionization-mass spectrometry (ESI-MS) that enables multiple analyses of a μL-sized sample with sensitivity and repeatability. In an analysis by droplet generator-assisted ESI-MS (DG-ESI-MS), a sample of μL volume is pulled into a sampling capillary and its equal nL-sized portions are generated by a droplet generator and analyzed by ESI-MS at time intervals of choice. The droplet generator is made of PMMA sheets by laser engraving conveniently and at a low cost. In a study to achieve effective ESI-MS detection of water-in-oil droplets, it's found that the problem of MS signal suppression by oil can be solved by using an appropriate organic carrier with ESI-enhancing additives. The proposed DG-ESI-MS method has linear calibration curves for both adenine and phenylalanine with LODs at the sub-μM level. Application of the present analytical platform for monitoring substrate concentration changes in an enzymatic reaction solution of 3 μL is demonstrated.
Collapse
Affiliation(s)
- Meiyuan Wang
- Department of Chemistry and Biochemistry, Jackson State University, Jackson, MS 39217, USA
| | - Xun Liao
- Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, Sichuan 610041, China
| | - Paul B. Tchounwou
- Department of Biology, Jackson State University, 1400 Lynch Street, Jackson, MS 39217, USA
| | - Yi-Ming Liu
- Department of Chemistry and Biochemistry, Jackson State University, Jackson, MS 39217, USA
| |
Collapse
|
6
|
Bell SE, Park I, Rubakhin SS, Bashir R, Vlasov Y, Sweedler JV. Droplet Microfluidics with MALDI-MS Detection: The Effects of Oil Phases in GABA Analysis. ACS MEASUREMENT SCIENCE AU 2021; 1:147-156. [PMID: 34939077 PMCID: PMC8679089 DOI: 10.1021/acsmeasuresciau.1c00017] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Indexed: 06/01/2023]
Abstract
Microfluidic and mass spectrometry (MS) methods are widely used to sample and probe the chemical composition of biological systems to elucidate chemical correlates of their healthy and disease states. Though matrix-assisted laser desorption/ionization-mass spectrometry (MALDI)-MS has been hyphenated to droplet microfluidics for offline analyses, the effects of parameters related to droplet generation, such as the type of oil phase used, have been understudied. To characterize these effects, five different oil phases were tested in droplet microfluidics for producing samples for MALDI-MS analysis. Picoliter to nanoliter aqueous droplets containing 0.1 to 100 mM γ-aminobutyric acid (GABA) and inorganic salts were generated inside a polydimethylsiloxane microfluidic chip and deposited onto a conductive glass slide. Optical microscopy, Raman spectroscopy, and MALDI-mass spectrometry imaging (MSI) of the droplet samples and surrounding areas revealed patterns of solvent and oil evaporation and analyte deposition. Optical microscopy detected the presence of salt crystals in 50-100 μm diameter dried droplets, and Raman and MSI were used to correlate GABA signals to the visible droplet footprints. MALDI-MS analyses revealed that droplets prepared in the presence of octanol oil led to the poorest detectability of GABA, whereas the oil phases containing FC-40 provided the best detectability; GABA signal was localized to the footprint of 65 pL droplets with a limit of detection of 23 amol. The effect of the surfactant perfluorooctanol on analyte detection was also investigated.
Collapse
Affiliation(s)
- Sara E. Bell
- Department
of Chemistry, University of Illinois Urbana−Champaign, Urbana, Illinois 61801, United States
- Beckman
Institute for Advanced Science and Technology, University of Illinois Urbana−Champaign, Urbana, Illinois 61801, United States
| | - Insu Park
- Holonyak
Micro & Nanotechnology Laboratory, University
of Illinois Urbana−Champaign, Urbana, Illinois 61801, United States
| | - Stanislav S. Rubakhin
- Department
of Chemistry, University of Illinois Urbana−Champaign, Urbana, Illinois 61801, United States
- Beckman
Institute for Advanced Science and Technology, University of Illinois Urbana−Champaign, Urbana, Illinois 61801, United States
| | - Rashid Bashir
- Beckman
Institute for Advanced Science and Technology, University of Illinois Urbana−Champaign, Urbana, Illinois 61801, United States
- Holonyak
Micro & Nanotechnology Laboratory, University
of Illinois Urbana−Champaign, Urbana, Illinois 61801, United States
- Department
of Electrical and Computer Engineering, University of Illinois Urbana−Champaign, Urbana, Illinois 61801, United States
- Department
of Bioengineering, University of Illinois
at Urbana−Champaign, Urbana, Illinois 61801, United States
| | - Yurii Vlasov
- Beckman
Institute for Advanced Science and Technology, University of Illinois Urbana−Champaign, Urbana, Illinois 61801, United States
- Holonyak
Micro & Nanotechnology Laboratory, University
of Illinois Urbana−Champaign, Urbana, Illinois 61801, United States
- Department
of Electrical and Computer Engineering, University of Illinois Urbana−Champaign, Urbana, Illinois 61801, United States
- Department
of Bioengineering, University of Illinois
at Urbana−Champaign, Urbana, Illinois 61801, United States
| | - Jonathan V. Sweedler
- Department
of Chemistry, University of Illinois Urbana−Champaign, Urbana, Illinois 61801, United States
- Beckman
Institute for Advanced Science and Technology, University of Illinois Urbana−Champaign, Urbana, Illinois 61801, United States
- Department
of Bioengineering, University of Illinois
at Urbana−Champaign, Urbana, Illinois 61801, United States
| |
Collapse
|
7
|
Wang Y, Xue P, Cao M, Yu T, Lane ST, Zhao H. Directed Evolution: Methodologies and Applications. Chem Rev 2021; 121:12384-12444. [PMID: 34297541 DOI: 10.1021/acs.chemrev.1c00260] [Citation(s) in RCA: 184] [Impact Index Per Article: 61.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Directed evolution aims to expedite the natural evolution process of biological molecules and systems in a test tube through iterative rounds of gene diversifications and library screening/selection. It has become one of the most powerful and widespread tools for engineering improved or novel functions in proteins, metabolic pathways, and even whole genomes. This review describes the commonly used gene diversification strategies, screening/selection methods, and recently developed continuous evolution strategies for directed evolution. Moreover, we highlight some representative applications of directed evolution in engineering nucleic acids, proteins, pathways, genetic circuits, viruses, and whole cells. Finally, we discuss the challenges and future perspectives in directed evolution.
Collapse
Affiliation(s)
- Yajie Wang
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States.,Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States.,DOE Center for Advanced Bioenergy and Bioproducts Innovation, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Pu Xue
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States.,Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States.,DOE Center for Advanced Bioenergy and Bioproducts Innovation, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Mingfeng Cao
- DOE Center for Advanced Bioenergy and Bioproducts Innovation, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Tianhao Yu
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States.,Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States.,DOE Center for Advanced Bioenergy and Bioproducts Innovation, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Stephan T Lane
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States.,DOE Center for Advanced Bioenergy and Bioproducts Innovation, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Huimin Zhao
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States.,Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States.,DOE Center for Advanced Bioenergy and Bioproducts Innovation, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States.,Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| |
Collapse
|
8
|
Abstract
Cell analysis is of great significance for the exploration of human diseases and health. However, there are not many techniques for high-throughput cell analysis in the simulated cell microenvironment. The high designability of the microfluidic chip enables multiple kinds of cells to be co-cultured on the chip, with other functions such as sample preprocessing and cell manipulation. Mass spectrometry (MS) can detect a large number of biomolecules without labelling. Therefore, the application of the microfluidic chip coupled with MS has represented a major branch of cell analysis over the past decades. Here, we concisely introduce various microfluidic devices coupled with MS used for cell analysis. The main functions of microfluidic devices are described first, followed by introductions of different interfaces with different types of MS. Then, their various applications in cell analysis are highlighted, with an emphasis on cell metabolism, drug screening, and signal transduction. Current limitations and prospective trends of microfluidics coupled with MS are discussed at the end.
Collapse
Affiliation(s)
- Wanling Zhang
- Department of Chemistry, Beijing Key Laboratory of Microanalytical Methods and Instrumentation, MOE Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology, Tsinghua University
| | - Qiang Zhang
- Department of Chemistry, Beijing Key Laboratory of Microanalytical Methods and Instrumentation, MOE Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology, Tsinghua University
| | - Jin-Ming Lin
- Department of Chemistry, Beijing Key Laboratory of Microanalytical Methods and Instrumentation, MOE Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology, Tsinghua University
| |
Collapse
|
9
|
Sohrabi S, Kassir N, Keshavarz Moraveji M. Droplet microfluidics: fundamentals and its advanced applications. RSC Adv 2020; 10:27560-27574. [PMID: 35516933 PMCID: PMC9055587 DOI: 10.1039/d0ra04566g] [Citation(s) in RCA: 85] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2020] [Revised: 09/03/2020] [Accepted: 07/09/2020] [Indexed: 01/09/2023] Open
Abstract
Droplet-based microfluidic systems have been shown to be compatible with many chemical and biological reagents and capable of performing a variety of operations that can be rendered programmable and reconfigurable. This platform has dimensional scaling benefits that have enabled controlled and rapid mixing of fluids in the droplet reactors, resulting in decreased reaction times. This, coupled with the precise generation and repeatability of droplet operations, has made the droplet-based microfluidic system a potent high throughput platform for biomedical research and applications. In addition to being used as micro-reactors ranging from the nano- to femtoliter (10-15 liters) range; droplet-based systems have also been used to directly synthesize particles and encapsulate many biological entities for biomedicine and biotechnology applications. For this, in the following article we will focus on the various droplet operations, as well as the numerous applications of the system and its future in many advanced scientific fields. Due to advantages of droplet-based systems, this technology has the potential to offer solutions to today's biomedical engineering challenges for advanced diagnostics and therapeutics.
Collapse
Affiliation(s)
- Somayeh Sohrabi
- Department of Chemical Engineering, Amirkabir University of Technology, Tehran Polytechnic Iran
| | - Nour Kassir
- Department of Chemical Engineering, Amirkabir University of Technology, Tehran Polytechnic Iran
| | | |
Collapse
|
10
|
Payne EM, Holland-Moritz DA, Sun S, Kennedy RT. High-throughput screening by droplet microfluidics: perspective into key challenges and future prospects. LAB ON A CHIP 2020; 20:2247-2262. [PMID: 32500896 DOI: 10.1039/d0lc00347f] [Citation(s) in RCA: 73] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
In two decades of development, impressive strides have been made for automating basic laboratory operations in droplet-based microfluidics, allowing the emergence of a new form of high-throughput screening and experimentation in nanoliter to femtoliter volumes. Despite advancements in droplet storage, manipulation, and analysis, the field has not yet been widely adapted for many high-throughput screening (HTS) applications. Broad adoption and commercial development of these techniques require robust implementation of strategies for the stable storage, chemical containment, generation of libraries, sample tracking, and chemical analysis of these small samples. We discuss these challenges for implementing droplet HTS and highlight key strategies that have begun to address these concerns. Recent advances in the field leave us optimistic about the future prospects of this rapidly developing technology.
Collapse
Affiliation(s)
- Emory M Payne
- Department of Chemistry, University of Michigan, Ann Arbor, MI, USA.
| | | | | | | |
Collapse
|
11
|
Hao Y, Jin N, Wang Q, Zhou Y, Zhao Y, Zhang X, Lü H. Dynamics and controllability of droplet fusion under gas-liquid-liquid three-phase flow in a microfluidic reactor. RSC Adv 2020; 10:14322-14330. [PMID: 35498473 PMCID: PMC9051941 DOI: 10.1039/d0ra00913j] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Accepted: 03/17/2020] [Indexed: 11/21/2022] Open
Abstract
Gas–liquid–liquid three-phase flow systems have unique advantages of controlling reagent manipulation and improving reaction performance. However, there remains a lack of insight into the dynamics and controllability of water droplet fusion assisted by gas bubbles, particularly scaling laws for use in the design and operation of complex multiphase flow processes. In the present work, a microfluidic reactor with three T-junctions was employed to sequentially generate gas bubbles and then fuse two dispersed water droplets. The formation of the dispersed phase was divided into multiple stages, and the bubble/droplet size was correlated with operating parameters. The formation of the second dispersed droplet at the third T-junction was accompanied by the fusion of the two dispersed water droplets that were formed. It revealed a two-stage process (i.e. drainage and fusion) for the two droplets to fuse while becoming mature by breaking-up with the secondary water supply stream. In addition, a droplet contact model was employed to understand the influence on the process stability and uniformity of the merged/fused droplets by varying the surfactant concentration (in oil), the viscosity of the water phase, and the flow rates of different fluids. The study provides a deeper understanding of the droplet fusion characteristics on gas–liquid–liquid three-phase flow in microreactors for a wide range of applications. Gas–liquid–liquid three-phase flow systems have unique advantages of controlling reagent manipulation and improving reaction performance.![]()
Collapse
Affiliation(s)
- Yanyan Hao
- College of Chemistry & Chemical Engineering, Yantai University Yantai 264005 China
| | - Nan Jin
- College of Chemistry & Chemical Engineering, Yantai University Yantai 264005 China
| | - Qingqiang Wang
- College of Chemistry & Chemical Engineering, Yantai University Yantai 264005 China
| | - Yufei Zhou
- College of Chemistry & Chemical Engineering, Yantai University Yantai 264005 China
| | - Yuchao Zhao
- College of Chemistry & Chemical Engineering, Yantai University Yantai 264005 China
| | - Xunli Zhang
- School of Engineering & Institute for Life Sciences, University of Southampton Southampton SO17 1BJ UK
| | - Hongying Lü
- College of Chemistry & Chemical Engineering, Yantai University Yantai 264005 China
| |
Collapse
|
12
|
Manipulation of gas-liquid-liquid systems in continuous flow microreactors for efficient reaction processes. J Flow Chem 2020. [DOI: 10.1007/s41981-019-00062-9] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
AbstractGas-liquid-liquid flow in microreactors holds great potential towards process intensification of operation in multiphase systems, particularly by a precise control over the three-phase contact patterns and the associated mass transfer enhancement. This work reviews the manipulation of gas-liquid-liquid three-phase flow in microreactors for carrying out efficient reaction processes, including gas-liquid-liquid reactions with catalysts residing in either liquid phase, coupling of a gas-liquid reaction with the liquid-liquid extraction, inert gas assisted liquid-liquid reactions and particle synthesis under three-phase flow. Microreactors are shown to be able to provide well-defined flow patterns and enhanced gas-liquid/liquid-liquid mass transfer rates towards the optimized system performance. The interplay between hydrodynamics and mass transfer, as well as its influence on the overall microreactor system performance is discussed. Meanwhile, future perspectives regarding the scale-up of gas-liquid-liquid microreactors in order to meet the industrial needs and their potential applications especially in biobased chemicals and fuels synthesis are further addressed.
Collapse
|
13
|
Markel U, Essani KD, Besirlioglu V, Schiffels J, Streit WR, Schwaneberg U. Advances in ultrahigh-throughput screening for directed enzyme evolution. Chem Soc Rev 2020; 49:233-262. [PMID: 31815263 DOI: 10.1039/c8cs00981c] [Citation(s) in RCA: 142] [Impact Index Per Article: 35.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Enzymes are versatile catalysts and their synthetic potential has been recognized for a long time. In order to exploit their full potential, enzymes often need to be re-engineered or optimized for a given application. (Semi-) rational design has emerged as a powerful means to engineer proteins, but requires detailed knowledge about structure function relationships. In turn, directed evolution methodologies, which consist of iterative rounds of diversity generation and screening, can improve an enzyme's properties with virtually no structural knowledge. Current diversity generation methods grant us access to a vast sequence space (libraries of >1012 enzyme variants) that may hide yet unexplored catalytic activities and selectivity. However, the time investment for conventional agar plate or microtiter plate-based screening assays represents a major bottleneck in directed evolution and limits the improvements that are obtainable in reasonable time. Ultrahigh-throughput screening (uHTS) methods dramatically increase the number of screening events per time, which is crucial to speed up biocatalyst design, and to widen our knowledge about sequence function relationships. In this review, we summarize recent advances in uHTS for directed enzyme evolution. We shed light on the importance of compartmentalization to preserve the essential link between genotype and phenotype and discuss how cells and biomimetic compartments can be applied to serve this function. Finally, we discuss how uHTS can inspire novel functional metagenomics approaches to identify natural biocatalysts for novel chemical transformations.
Collapse
Affiliation(s)
- Ulrich Markel
- Institute of Biotechnology, RWTH Aachen University, Worringer Weg 3, 52074 Aachen, Germany.
| | | | | | | | | | | |
Collapse
|
14
|
Holland-Moritz DA, Wismer MK, Mann BF, Farasat I, Devine P, Guetschow ED, Mangion I, Welch CJ, Moore JC, Sun S, Kennedy RT. Mass Activated Droplet Sorting (MADS) Enables High-Throughput Screening of Enzymatic Reactions at Nanoliter Scale. Angew Chem Int Ed Engl 2020; 59:4470-4477. [PMID: 31868984 DOI: 10.1002/anie.201913203] [Citation(s) in RCA: 87] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Revised: 11/21/2019] [Indexed: 01/02/2023]
Abstract
Microfluidic droplet sorting enables the high-throughput screening and selection of water-in-oil microreactors at speeds and volumes unparalleled by traditional well-plate approaches. Most such systems sort using fluorescent reporters on modified substrates or reactions that are rarely industrially relevant. We describe a microfluidic system for high-throughput sorting of nanoliter droplets based on direct detection using electrospray ionization mass spectrometry (ESI-MS). Droplets are split, one portion is analyzed by ESI-MS, and the second portion is sorted based on the MS result. Throughput of 0.7 samples s-1 is achieved with 98 % accuracy using a self-correcting and adaptive sorting algorithm. We use the system to screen ≈15 000 samples in 6 h and demonstrate its utility by sorting 25 nL droplets containing transaminase expressed in vitro. Label-free ESI-MS droplet screening expands the toolbox for droplet detection and recovery, improving the applicability of droplet sorting to protein engineering, drug discovery, and diagnostic workflows.
Collapse
Affiliation(s)
| | - Michael K Wismer
- Scientific Engineering and Design, Merck & Co., Inc., 2000 Galloping Hill Road, Kenilworth, NJ, 07033, USA
| | - Benjamin F Mann
- Process Research and Development, Merck & Co., Inc., 126 E. Lincoln Ave, Rahway, NJ, 07065, USA
| | - Iman Farasat
- Janssen R&D, 1400 McKean Rd., Spring House, PA, 19477, USA
| | - Paul Devine
- Process Research and Development, Merck & Co., Inc., 126 E. Lincoln Ave, Rahway, NJ, 07065, USA
| | - Erik D Guetschow
- Process Research and Development, Merck & Co., Inc., 126 E. Lincoln Ave, Rahway, NJ, 07065, USA
| | - Ian Mangion
- Process Research and Development, Merck & Co., Inc., 126 E. Lincoln Ave, Rahway, NJ, 07065, USA
| | | | - Jeffrey C Moore
- Process Research and Development, Merck & Co., Inc., 126 E. Lincoln Ave, Rahway, NJ, 07065, USA
| | - Shuwen Sun
- Process Research and Development, Merck & Co., Inc., 126 E. Lincoln Ave, Rahway, NJ, 07065, USA
| | - Robert T Kennedy
- Dept. of Chemistry, University of Michigan, 930 N University, Ann Abor, MI, 48109, USA
| |
Collapse
|
15
|
Holland‐Moritz DA, Wismer MK, Mann BF, Farasat I, Devine P, Guetschow ED, Mangion I, Welch CJ, Moore JC, Sun S, Kennedy RT. Mass Activated Droplet Sorting (MADS) Enables High‐Throughput Screening of Enzymatic Reactions at Nanoliter Scale. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.201913203] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
| | - Michael K. Wismer
- Scientific Engineering and Design Merck & Co., Inc. 2000 Galloping Hill Road Kenilworth NJ 07033 USA
| | - Benjamin F. Mann
- Process Research and Development Merck & Co., Inc. 126 E. Lincoln Ave Rahway NJ 07065 USA
| | - Iman Farasat
- Janssen R&D 1400 McKean Rd. Spring House PA 19477 USA
| | - Paul Devine
- Process Research and Development Merck & Co., Inc. 126 E. Lincoln Ave Rahway NJ 07065 USA
| | - Erik D. Guetschow
- Process Research and Development Merck & Co., Inc. 126 E. Lincoln Ave Rahway NJ 07065 USA
| | - Ian Mangion
- Process Research and Development Merck & Co., Inc. 126 E. Lincoln Ave Rahway NJ 07065 USA
| | | | - Jeffrey C. Moore
- Process Research and Development Merck & Co., Inc. 126 E. Lincoln Ave Rahway NJ 07065 USA
| | - Shuwen Sun
- Process Research and Development Merck & Co., Inc. 126 E. Lincoln Ave Rahway NJ 07065 USA
| | - Robert T. Kennedy
- Dept. of Chemistry University of Michigan 930 N University Ann Abor MI 48109 USA
| |
Collapse
|
16
|
Jankowski P, Kutaszewicz R, Ogończyk D, Garstecki P. A microfluidic platform for screening and optimization of organic reactions in droplets. J Flow Chem 2019. [DOI: 10.1007/s41981-019-00055-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
|
17
|
A Liquid-Metal-Based Dielectrophoretic Microdroplet Generator. MICROMACHINES 2019; 10:mi10110769. [PMID: 31718029 PMCID: PMC6915379 DOI: 10.3390/mi10110769] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Revised: 11/04/2019] [Accepted: 11/07/2019] [Indexed: 02/06/2023]
Abstract
This paper proposes a novel microdroplet generator based on the dielectrophoretic (DEP) force. Unlike the conventional continuous microfluidic droplet generator, this droplet generator is more like “invisible electric scissors”. It can cut the droplet off from the fluid matrix and modify droplets’ length precisely by controlling the electrodes’ length and position. These electrodes are made of liquid metal by injection. By applying a certain voltage on the liquid-metal electrodes, the electrodes generate an uneven electric field inside the main microfluidic channel. Then, the uneven electric field generates DEP force inside the fluid. The DEP force shears off part from the main matrix, in order to generate droplets. To reveal the mechanism, numerical simulations were performed to analyze the DEP force. A detailed experimental parametric study was also performed. Unlike the traditional droplet generators, the main separating force of this work is DEP force only, which can produce one droplet at a time in a more precise way.
Collapse
|
18
|
Grant J, O’Kane PT, Kimmel BR, Mrksich M. Using Microfluidics and Imaging SAMDI-MS To Characterize Reaction Kinetics. ACS CENTRAL SCIENCE 2019; 5:486-493. [PMID: 30937376 PMCID: PMC6439460 DOI: 10.1021/acscentsci.8b00867] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Indexed: 06/09/2023]
Abstract
Microfluidic platforms have enabled the simplification of biochemical assays with a significant reduction in the use of reagents, yet the current methods available for analyzing reaction products can limit applications of these approaches. This paper demonstrates a simple microfluidic device that incorporates a functionalized self-assembled monolayer to measure the rate constant for a chemical reaction. The device mixes the reactants and allows them to selectively immobilize to the monolayer at the base of a microfluidic channel in a time-dependent manner as they flow down the channel. Imaging self-assembled monolayers for matrix-assisted laser desorption/ionization mass spectrometry (iSAMDI-MS) is used to acquire a quantitative image representing the time-resolved progress of the reaction as it flowed through the channel. Knowledge of the surface immobilization chemistry and the fluid front characteristics allows for the determination of the chemical reaction rate constant. This approach widens the applicability of microfluidics for chemical reaction monitoring and establishes a label-free method for studying processes that occur within a dispersive regime.
Collapse
Affiliation(s)
- Jennifer Grant
- Department
of Chemistry, Department of Chemical & Biological Engineering,
and Department of
Biomedical Engineering, Northwestern University, Evanston, Illinois 60208, United States
| | - Patrick T. O’Kane
- Department
of Chemistry, Department of Chemical & Biological Engineering,
and Department of
Biomedical Engineering, Northwestern University, Evanston, Illinois 60208, United States
| | - Blaise R. Kimmel
- Department
of Chemistry, Department of Chemical & Biological Engineering,
and Department of
Biomedical Engineering, Northwestern University, Evanston, Illinois 60208, United States
| | - Milan Mrksich
- Department
of Chemistry, Department of Chemical & Biological Engineering,
and Department of
Biomedical Engineering, Northwestern University, Evanston, Illinois 60208, United States
| |
Collapse
|
19
|
Grant J, Goudarzi SH, Mrksich M. High-Throughput Enzyme Kinetics with 3D Microfluidics and Imaging SAMDI Mass Spectrometry. Anal Chem 2018; 90:13096-13103. [DOI: 10.1021/acs.analchem.8b04391] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
|
20
|
Abstract
Droplet microfluidic systems have evolved as fluidic platforms that use much less sample volume and provide high throughput for biochemical analysis compared to conventional microfluidic devices. The variety of droplet fluidic applications triggered several detection techniques to be applied for analysis of droplets. In this review, we focus on label-free droplet detection techniques that were adapted to various droplet microfluidic platforms. We provide a classification of most commonly used droplet platform technologies. Then we discuss the examples of various label-free droplet detection schemes implemented for these platforms. While providing the research landscape for label-free droplet detection methods, we aim to highlight the strengths and shortcomings of each droplet platform so that a more targeted approach can be taken by researchers when selecting a droplet platform and a detection scheme for any given application.
Collapse
|
21
|
Bao L, Spandan V, Yang Y, Dyett B, Verzicco R, Lohse D, Zhang X. Flow-induced dissolution of femtoliter surface droplet arrays. LAB ON A CHIP 2018; 18:1066-1074. [PMID: 29487930 DOI: 10.1039/c7lc01321c] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
The dissolution of liquid nanodroplets is a crucial step in many applied processes, such as separation and dispersion in the food industry, crystal formation of pharmaceutical products, concentrating and analysis in medical diagnosis, and drug delivery in aerosols. In this work, using both experiments and numerical simulations, we quantitatively study the dissolution dynamics of femtoliter surface droplets in a highly ordered array under a uniform flow. Our results show that the dissolution of femtoliter droplets strongly depends on their spatial positions relative to the flow direction, drop-to-drop spacing in the array, and the imposed flow rate. In some particular cases, the droplet at the edge of the array can dissolve about 30% faster than the ones located near the centre. The dissolution rate of the droplet increases by 60% as the inter-droplet spacing is increased from 2.5 μm to 20 μm. Moreover, the droplets close to the front of the flow commence to shrink earlier than those droplets in the center of the array. The average dissolution rate is faster for the faster flow. As a result, the dissolution time (Ti) decreases with the Reynolds number (Re) of the flow as Ti ∝ Re-3/4. The experimental results are in good agreement with the numerical simulations where the advection-diffusion equation for the concentration field is solved and the concentration gradient on the surface of the drop is computed. The findings suggest potential approaches to manipulate nanodroplet sizes in droplet arrays simply by dissolution controlled by an external flow. The obtained droplets with varying curvatures may serve as templates for generating multifocal microlenses in one array.
Collapse
Affiliation(s)
- Lei Bao
- Soft Matter & Interfaces Group, School of Engineering, RMIT University, Melbourne, VIC 3001, Australia
| | | | | | | | | | | | | |
Collapse
|
22
|
DMF-MALDI: droplet based microfluidic combined to MALDI-TOF for focused peptide detection. Sci Rep 2017; 7:6756. [PMID: 28754890 PMCID: PMC5533719 DOI: 10.1038/s41598-017-06660-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Accepted: 06/13/2017] [Indexed: 12/21/2022] Open
Abstract
We present an automated droplet microfluidic system (DMF) to generate monitored nanoliter aqueous droplets in oil and their deposition on a commercial stainless steel plate for MALDI-TOF analysis of peptides or protein digests. We demonstrate that DMF-MALDI combination focuses the analyte on the MALDI plate, increasing considerably the homogeneity of the dried material. This results in a 30times enhanced MALDI-TOF MS signal for a model peptide, allowing a significant improvement of the detection sensitivity limit (down to few tens of attomoles). Moreover, positive detection can be achieved from sub-nanomolar peptides solutions and better overall protein sequence coverages are obtained from few tens attomoles of protein digest. These results make DMF-MALDI a promising approach for the treatment of peptides samples as well as a key component for an integrated approach in the proteomic field.
Collapse
|
23
|
Kundys M, Nejbauer M, Jönsson-Niedziolka M, Adamiak W. Generation–Collection Electrochemistry Inside a Rotating Droplet. Anal Chem 2017; 89:8057-8063. [DOI: 10.1021/acs.analchem.7b01533] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Magdalena Kundys
- Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland
| | - Michal Nejbauer
- Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland
| | | | - Wojciech Adamiak
- Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland
| |
Collapse
|
24
|
Beulig RJ, Warias R, Heiland JJ, Ohla S, Zeitler K, Belder D. A droplet-chip/mass spectrometry approach to study organic synthesis at nanoliter scale. LAB ON A CHIP 2017; 17:1996-2002. [PMID: 28513728 DOI: 10.1039/c7lc00313g] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
A droplet-based microfluidic device with seamless hyphenation to electrospray mass spectrometry was developed to rapidly investigate organic reactions in segmented flow providing a versatile tool for drug development. A chip-MS interface with an integrated counterelectrode allowed for a flexible positioning of the chip-emitter in front of the MS orifice as well as an independent adjustment of the electrospray potentials. This was necessary to avoid contamination of the mass spectrometer as well as sample overloading due to the high analyte concentrations. The device was exemplarily applied to study the scope of an amino-catalyzed domino reaction with low picomole amount of catalyst in individual nanoliter sized droplets.
Collapse
Affiliation(s)
- R J Beulig
- Institute for Analytical Chemistry, University of Leipzig, Linnéstraße 3, 04103 Leipzig, Germany.
| | | | | | | | | | | |
Collapse
|
25
|
Abstract
Droplet microfluidics generates and manipulates discrete droplets through immiscible multiphase flows inside microchannels. Due to its remarkable advantages, droplet microfluidics bears significant value in an extremely wide range of area. In this review, we provide a comprehensive and in-depth insight into droplet microfluidics, covering fundamental research from microfluidic chip fabrication and droplet generation to the applications of droplets in bio(chemical) analysis and materials generation. The purpose of this review is to convey the fundamentals of droplet microfluidics, a critical analysis on its current status and challenges, and opinions on its future development. We believe this review will promote communications among biology, chemistry, physics, and materials science.
Collapse
Affiliation(s)
- Luoran Shang
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University , Nanjing 210096, China
| | - Yao Cheng
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University , Nanjing 210096, China
| | - Yuanjin Zhao
- State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University , Nanjing 210096, China
| |
Collapse
|
26
|
Saha-Shah A, Green CM, Abraham DH, Baker LA. Segmented flow sampling with push-pull theta pipettes. Analyst 2017; 141:1958-65. [PMID: 26907673 DOI: 10.1039/c6an00028b] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
We report development of a mobile and easy-to-fabricate theta pipette microfluidic device for segmented flow sampling. The theta pipettes were also used as electrospray emitters for analysis of sub-nanoliter segments, which resulted in delivery of analyte to the vacuum inlet of the mass spectrometer without multiple transfer steps. Theta pipette probes enable sample collection with high spatial resolution due to micron or smaller sized probe inlets and can be used to manipulate aqueous segments in the range of 200 pL to tens of nanoliters. Optimized conditions can enable sampling with high spatial and temporal resolution, suitable for chemical monitoring in biological samples and studies of sample heterogeneity. Intercellular heterogeneity among Allium cepa cells was studied by collecting cytoplasm from multiple cells using a single probe. Extracted cytoplasm was analyzed in a fast and high throughput manner by direct electrospray mass spectrometry of segmented sample from the probe tip.
Collapse
Affiliation(s)
- Anumita Saha-Shah
- Department of Chemistry, Indiana University, 800 E. Kirkwood Avenue, Bloomington, IN 47405, USA.
| | - Curtis M Green
- Department of Chemistry, Indiana University, 800 E. Kirkwood Avenue, Bloomington, IN 47405, USA.
| | - David H Abraham
- Department of Chemistry, Indiana University, 800 E. Kirkwood Avenue, Bloomington, IN 47405, USA.
| | - Lane A Baker
- Department of Chemistry, Indiana University, 800 E. Kirkwood Avenue, Bloomington, IN 47405, USA.
| |
Collapse
|
27
|
Robertson K. Using flow technologies to direct the synthesis and assembly of materials in solution. Chem Cent J 2017; 11:4. [PMID: 28101131 PMCID: PMC5215996 DOI: 10.1186/s13065-016-0229-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2016] [Accepted: 12/02/2016] [Indexed: 02/08/2023] Open
Abstract
In the pursuit of materials with structure-related function, directing the assembly of materials is paramount. The resultant structure can be controlled by ordering of reactants, spatial confinement and control over the reaction/crystallisation times and stoichiometries. These conditions can be administered through the use of flow technologies as evidenced by the growing widespread application of microfluidics for the production of nanomaterials; the function of which is often dictated or circumscribed by size. In this review a range of flow technologies is explored for use in the control of self-assembled systems: including techniques for reagent ordering, mixing control and high-throughput optimisation. The examples given encompass organic, inorganic and biological systems and focus on control of shape, function, composition and size.Graphical abstract.
Collapse
Affiliation(s)
- K Robertson
- Department of Chemistry, University of Bath, Bath, BA2 7AY UK
| |
Collapse
|
28
|
Reizman BJ, Wang YM, Buchwald SL, Jensen KF. Suzuki-Miyaura cross-coupling optimization enabled by automated feedback. REACT CHEM ENG 2016; 1:658-666. [PMID: 27928513 PMCID: PMC5123644 DOI: 10.1039/c6re00153j] [Citation(s) in RCA: 95] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2016] [Accepted: 09/27/2016] [Indexed: 12/16/2022]
Abstract
An automated, droplet-flow microfluidic system explores and optimizes Pd-catalyzed Suzuki-Miyaura cross-coupling reactions. A smart optimal DoE-based algorithm is implemented to increase the turnover number and yield of the catalytic system considering both discrete variables-palladacycle and ligand-and continuous variables-temperature, time, and loading-simultaneously. The use of feedback allows for experiments to be run with catalysts and under conditions more likely to produce an optimum; consequently complex reaction optimizations are completed within 96 experiments. Response surfaces predicting reaction performance near the optima are generated and validated. From the screening results, shared attributes of successful precatalysts are identified, leading to improved understanding of the influence of ligand selection upon transmetalation and oxidative addition in the reaction mechanism. Dialkylbiarylphosphine, trialkylphosphine, and bidentate ligands are assessed.
Collapse
Affiliation(s)
- Brandon J Reizman
- Department of Chemical Engineering , Novartis-MIT Center for Continuous Manufacturing , Massachusetts Institute of Technology , 77 Massachusetts Avenue , Cambridge , MA 02139 , USA .
| | - Yi-Ming Wang
- Department of Chemistry , Novartis-MIT Center for Continuous Manufacturing , Massachusetts Institute of Technology , 77 Massachusetts Avenue , Cambridge , MA 02139 , USA .
| | - Stephen L Buchwald
- Department of Chemistry , Novartis-MIT Center for Continuous Manufacturing , Massachusetts Institute of Technology , 77 Massachusetts Avenue , Cambridge , MA 02139 , USA .
| | - Klavs F Jensen
- Department of Chemical Engineering , Novartis-MIT Center for Continuous Manufacturing , Massachusetts Institute of Technology , 77 Massachusetts Avenue , Cambridge , MA 02139 , USA .
| |
Collapse
|
29
|
Fernandez Rivas D, Kuhn S. Synergy of Microfluidics and Ultrasound : Process Intensification Challenges and Opportunities. Top Curr Chem (Cham) 2016; 374:70. [PMID: 27654863 PMCID: PMC5480412 DOI: 10.1007/s41061-016-0070-y] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2016] [Accepted: 08/30/2016] [Indexed: 11/25/2022]
Abstract
A compact snapshot of the current convergence of novel developments relevant to chemical engineering is given. Process intensification concepts are analysed through the lens of microfluidics and sonochemistry. Economical drivers and their influence on scientific activities are mentioned, including innovation opportunities towards deployment into society. We focus on the control of cavitation as a means to improve the energy efficiency of sonochemical reactors, as well as in the solids handling with ultrasound; both are considered the most difficult hurdles for its adoption in a practical and industrial sense. Particular examples for microfluidic clogging prevention, numbering-up and scaling-up strategies are given. To conclude, an outlook of possible new directions of this active and promising combination of technologies is hinted.
Collapse
Affiliation(s)
- David Fernandez Rivas
- Mesoscale Chemical Systems, MESA+ Institute for Nanotechnology, Carre 1.339, 7500 AE Enschede, The Netherlands
| | - Simon Kuhn
- Department of Chemical Engineering, KU Leuven, Celestijnenlaan 200F, 3001 Leuven, Belgium
| |
Collapse
|
30
|
Abstract
The pharmaceutical industry is investing in continuous flow and high-throughput experimentation as tools for rapid process development accelerated scale-up. Coupled with automation, these technologies offer the potential for comprehensive reaction characterization and optimization, but with the cost of conducting exhaustive multifactor screens. Automated feedback in flow offers researchers an alternative strategy for efficient characterization of reactions based on the use of continuous technology to control chemical reaction conditions and optimize in lieu of screening. Optimization with feedback allows experiments to be conducted where the most information can be gained from the chemistry, enabling product yields to be maximized and kinetic models to be generated while the total number of experiments is minimized. This Account opens by reviewing select examples of feedback optimization in flow and applications to chemical research. Systems in the literature are classified into (i) deterministic "black box" optimization systems that do not model the reaction system and are therefore limited in the utility of results for scale-up, (ii) deterministic model-based optimization systems from which reaction kinetics and/or mechanisms can be automatically evaluated, and (iii) stochastic systems. Though diverse in application, flow feedback systems have predominantly focused upon the optimization of continuous variables, i.e., variables such as time, temperature, and concentration that can be ramped from one experiment to the next. Unfortunately, this implies that the screening of discrete variables such as catalyst, ligand, or solvent generally does not factor into automated flow optimization, resulting in incomplete process knowledge. Herein, we present a system and strategy developed for optimizing discrete and continuous variables of a chemical reaction simultaneously. The approach couples automated feedback with high-throughput reaction screening in droplet flow microfluidics. This Account details the system configuration for on-demand creation of sub-20 μL droplets with interchangeable reagents and catalysts. These droplets are reacted in a fully automated microfluidic system and analyzed online by LC/MS. Feeding back from the online analytical results, a design of experiments (DoE)-based adaptive response surface algorithm is employed that deductively removes candidate reagents from the optimization as optimal reaction conditions are refined, leading to rapid convergence. Using the automated optimization platform, case studies are presented for solvent selection in a competitive alkylation chemistry and for catalyst-ligand selection in heteroaromatic Suzuki-Miyaura cross-coupling chemistries. For the monoalkylation of trans-1,2-diaminocyclohexane, polar aprotic solvents at moderate temperatures are shown to be favorable, with optimality accurately identified with dimethyl sulfoxide as the solvent in 67 experiments. For Suzuki-Miyaura cross-couplings, the optimality of precatalysts and continuous variable conditions are observed to change in accordance with the coupling reagents, providing insights into catalyst behavior in the context of the reaction mechanism. Future opportunities in automated reaction development include the incorporation of chemoinformatics for faster analysis and machine-learning algorithms to guide and optimize the synthesis. Adoption of this technology stands to reduce graduate student and postdoc time on routine tasks in the laboratory, while feeding back knowledge used to guide new research directions. Moreover, the application of this technology in industry promises to lessen the cost and time associated with advancing pharmaceutical molecules through development and scale-up.
Collapse
Affiliation(s)
- Brandon J. Reizman
- Department of Chemical Engineering,
Novartis Center for Continuous Manufacturing, Massachusetts Institute of Technology, Room 66-542A, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
| | - Klavs F. Jensen
- Department of Chemical Engineering,
Novartis Center for Continuous Manufacturing, Massachusetts Institute of Technology, Room 66-542A, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
| |
Collapse
|
31
|
Are fluorine-rich pharmaceuticals lost by partition into fluorous phases? J Pharm Biomed Anal 2016; 128:106-110. [PMID: 27239759 DOI: 10.1016/j.jpba.2016.05.025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Revised: 05/13/2016] [Accepted: 05/16/2016] [Indexed: 11/24/2022]
Abstract
The recently developed technology of droplet microfluidics has demonstrated great potential for many applications such as biochemical assay, high throughput screening, cell culture, directed evolution, and chemical synthesis. Intrigued by its capabilities for miniaturization, flexible manipulation, rapid reagent mixing and high throughput experimentation and analysis, the pharmaceutical industry has begun to investigate droplet microfluidic implementation in medicinal and process chemistry. Segmented by an immiscible secondary phase, usually perfluorinated oil, aqueous or organic droplets serve as individual micro-reactors without suffering cross-contamination. As many drug molecules contain fluorines, it is necessary to investigate whether such compounds will be preferentially extracted into the fluorous phase via fluorophilic solvation, which could lead to erroneous analytical results. In this work, we chose drugs with up to 10 fluorines to probe their partition into perfluorodecalin (PFD) from a variety of organic solvents. A fast and straightforward MISER (Multiple Injections in a Single Experimental Run) LC-MS method was applied to measure the loss of drug after mixing with PFD. We found that no significant partition occurred, with the concentration of drugs in the 'experimental' group measured as ±10% of the 'control' group. The RSD% of multiple injections is <5%. The finding was further validated by the conventional LC-MS approach.
Collapse
|
32
|
Guardingo M, Busqué F, Ruiz-Molina D. Reactions in ultra-small droplets by tip-assisted chemistry. Chem Commun (Camb) 2016; 52:11617-26. [PMID: 27468750 DOI: 10.1039/c6cc03504c] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The confinement of chemical reactions within small droplets has received much attention in the last few years. This approach has been proved successful for the in-depth study of naturally occurring chemical processes as well as for the synthesis of different sets of nanomaterials with control over their size, shape and properties. Different approaches such as the use of self-contained structures or microfluidic generated droplets have been followed over the years with success. However, novel approaches have emerged during the last years based on the deposition of femtolitre-sized droplets on surfaces using tip-assisted lithographic methods. In this feature article, we review the advances made towards the use of these ultra-small droplets patterned on surfaces as confined nano-reactors.
Collapse
Affiliation(s)
- M Guardingo
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and The Barcelona Institute of Science and Technology, Campus UAB, Bellaterra 08193, Barcelona, Spain.
| | | | | |
Collapse
|
33
|
Shembekar N, Chaipan C, Utharala R, Merten CA. Droplet-based microfluidics in drug discovery, transcriptomics and high-throughput molecular genetics. LAB ON A CHIP 2016; 16:1314-31. [PMID: 27025767 DOI: 10.1039/c6lc00249h] [Citation(s) in RCA: 210] [Impact Index Per Article: 26.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Droplet-based microfluidics enables assays to be carried out at very high throughput (up to thousands of samples per second) and enables researchers to work with very limited material, such as primary cells, patient's biopsies or expensive reagents. An additional strength of the technology is the possibility to perform large-scale genotypic or phenotypic screens at the single-cell level. Here we critically review the latest developments in antibody screening, drug discovery and highly multiplexed genomic applications such as targeted genetic workflows, single-cell RNAseq and single-cell ChIPseq. Starting with a comprehensive introduction for non-experts, we pinpoint current limitations, analyze how they might be overcome and give an outlook on exciting future applications.
Collapse
Affiliation(s)
- Nachiket Shembekar
- European Molecular Biology Laboratory (EMBL), Genome Biology Unit, Meyerhofstrasse 1, Heidelberg, Germany.
| | - Chawaree Chaipan
- European Molecular Biology Laboratory (EMBL), Genome Biology Unit, Meyerhofstrasse 1, Heidelberg, Germany.
| | - Ramesh Utharala
- European Molecular Biology Laboratory (EMBL), Genome Biology Unit, Meyerhofstrasse 1, Heidelberg, Germany.
| | - Christoph A Merten
- European Molecular Biology Laboratory (EMBL), Genome Biology Unit, Meyerhofstrasse 1, Heidelberg, Germany.
| |
Collapse
|
34
|
Hu C, Yen A, Joshi N, Hartman RL. Packed-bed microreactors for understanding of the dissolution kinetics and mechanisms of asphaltenes in xylenes. Chem Eng Sci 2016. [DOI: 10.1016/j.ces.2015.10.022] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
|
35
|
Kasule JS, Maddala J, Mobed P, Rengaswamy R. Very large scale droplet microfluidic integration (VLDMI) using genetic algorithm. Comput Chem Eng 2016. [DOI: 10.1016/j.compchemeng.2015.10.018] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
|
36
|
Huang H, He X. Fluid displacement during droplet formation at microfluidic flow-focusing junctions. LAB ON A CHIP 2015; 15:4197-205. [PMID: 26381220 PMCID: PMC4605896 DOI: 10.1039/c5lc00730e] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Microdroplets and microcapsules have been widely produced using microfluidic flow-focusing junctions for biomedical and chemical applications. However, the multiphase microfluidic flow at the flow-focusing junction has not been well investigated. In this study, the displacement of two (core and shell) aqueous fluids that disperse into droplets altogether in a carrier oil emulsion was investigated both numerically and experimentally. It was found that extensive displacement of the two aqueous fluids within the droplet during its formation could occur as a result of the shear effect of the carrier fluid and the capillary effect of interfacial tension. We further identified that the two mechanisms of fluid displacement can be evaluated by two dimensionless parameters. The quantitative relationship between the degree of fluid displacement and these two dimensionless parameters was determined experimentally. Finally, we demonstrated that the degree of fluid displacement could be controlled to generate hydrogel microparticles of different morphologies using planar or nonplanar flow-focusing junctions. These findings should provide useful guidance to the microfluidic production of microscale droplets or capsules for various biomedical and chemical applications.
Collapse
Affiliation(s)
- Haishui Huang
- Department of Mechanical and Aerospace Engineering, The Ohio State University, Columbus, Ohio 43210, USA
- Department of Biomedical Engineering, The Ohio State University, Columbus, Ohio 43210, USA
| | - Xiaoming He
- Department of Biomedical Engineering, The Ohio State University, Columbus, Ohio 43210, USA
- Davis Heart and Lung Research Institute, The Ohio State University, Columbus, Ohio 43210, USA
- Comprehensive Cancer Center, The Ohio State University, Columbus, Ohio 43210, USA
| |
Collapse
|
37
|
Chen YC, Liu K, Shen CKF, van Dam RM. On-demand generation and mixing of liquid-in-gas slugs with digitally-programmable composition and size. JOURNAL OF MICROMECHANICS AND MICROENGINEERING : STRUCTURES, DEVICES, AND SYSTEMS 2015; 25:084006. [PMID: 29167603 PMCID: PMC5695874 DOI: 10.1088/0960-1317/25/8/084006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Microscopic droplets or slugs of mixed reagents provide a convenient platform for performing large numbers of isolated biochemical or chemical reactions for many screening and optimization applications. Myriad microfluidic approaches have emerged for creating droplets or slugs with controllable size and composition, generally using an immiscible carrier fluid to assist with the formation or merging processes. We report a novel device for generation of liquid slugs in air when the use of a carrier liquid is not compatible with the application. The slug generator contains two adjacent chambers, each of which has a volume that can be digitally adjusted by closing selected microvalves. Reagents are filled into the two chambers, merged together into a contiguous liquid slug, ejected at the desired time from the device using gas pressure, and mixed by flowing in a downstream channel. Programmable size and composition of slugs is achieved by dynamically adjusting the volume of each chamber prior to filling. Slug formation in this fashion is independent of fluid properties and can easily be scaled to mix larger numbers of reagents. This device has already been used to screen monomer ratios in supramolecular nanoparticle assembly and radiolabeling conditions of engineered antibodies, and here we provide a detailed description of the underlying device.
Collapse
Affiliation(s)
| | | | - Clifton Kwang-Fu Shen
- Department of Molecular & Medical Pharmacology and Crump Institute for Molecular Imaging, David Geffen School of Medicine, University of California, Los Angeles, 570 Westwood Plaza, Los Angeles, CA 90095
| | - R. Michael van Dam
- Department of Molecular & Medical Pharmacology and Crump Institute for Molecular Imaging, David Geffen School of Medicine, University of California, Los Angeles, 570 Westwood Plaza, Los Angeles, CA 90095
| |
Collapse
|
38
|
Electrochemical droplet-based microfluidics using chip-based carbon paste electrodes for high-throughput analysis in pharmaceutical applications. Anal Chim Acta 2015; 883:45-54. [DOI: 10.1016/j.aca.2015.03.008] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2014] [Revised: 02/10/2015] [Accepted: 03/04/2015] [Indexed: 11/27/2022]
|
39
|
Reizman BJ, Jensen KF. Simultaneous solvent screening and reaction optimization in microliter slugs. Chem Commun (Camb) 2015. [DOI: 10.1039/c5cc03651h] [Citation(s) in RCA: 64] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
An automated microfluidic system rapidly discovers optimal and scalable reaction conditions for alkylation while teasing-out integrated discrete and continuous variable relationships.
Collapse
Affiliation(s)
- Brandon J. Reizman
- Department of Chemical Engineering
- Novartis-MIT Center for Continuous Manufacturing
- Massachusetts Institute of Technology
- Cambridge
- USA
| | - Klavs F. Jensen
- Department of Chemical Engineering
- Novartis-MIT Center for Continuous Manufacturing
- Massachusetts Institute of Technology
- Cambridge
- USA
| |
Collapse
|
40
|
Jensen KF, Reizman BJ, Newman SG. Tools for chemical synthesis in microsystems. LAB ON A CHIP 2014; 14:3206-12. [PMID: 24865228 DOI: 10.1039/c4lc00330f] [Citation(s) in RCA: 106] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Chemical synthesis in microsystems has evolved from simple proof-of-principle examples to become a general technique in academia and industry. Numerous such "flow chemistry" applications are now found in pharmaceutical and fine chemical synthesis. Much of the development has been based on systems employing macroscopic flow components and tubes, rather than the integrated chip technology envisioned by the lab-on-a-chip community. We review the major developments in systems for flow chemistry and discuss limitations underlying the development of chip-scale integrated systems.
Collapse
Affiliation(s)
- Klavs F Jensen
- Department of Chemical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge MA 02139, USA.
| | | | | |
Collapse
|
41
|
Ban T, Tani K, Nakata H, Okano Y. Self-propelled droplets for extracting rare-earth metal ions. SOFT MATTER 2014; 10:6316-6320. [PMID: 25029997 DOI: 10.1039/c4sm01001a] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
We have developed self-propelled droplets having the abilities to detect a chemical gradient, to move toward a higher concentration of a specific metal ion (particularly the dysprosium ion), and to extract it. Such abilities rely on the high surface activity of di(2-ethylhexyl) phosphoric acid (DEHPA) in response to pH and the affinity of DEHPA for the dysprosium ion. We used two external stimuli as chemical signals to control droplet motion: a pH signal to induce motility and metal ions to induce directional sensing. The oil droplets loaded with DEHPA spontaneously move around beyond the threshold of pH even in a homogeneous pH field. In the presence of a gel block containing metal ions, the droplets show directional sensing and their motility is biased toward higher concentrations. The metal ions investigated can be arranged in decreasing order of directional sensing as Dy(3+)≫ Nd(3+) > Y(3+) > Gd(3+). Furthermore, the analysis of components by using an atomic absorption spectrophotometer reveals that the metal ions can be extracted from the environmental media to the interiors of the droplets. This system may offer alternative self-propelled nano/microscale machines to bubble thrust engines powered by asymmetrical catalysts.
Collapse
Affiliation(s)
- Takahiko Ban
- Department of Materials Engineering Science, Graduate School of Engineering Science, Osaka University, Machikaneyamacho 1-3, Toyonaka City, Osaka 560-8531, Japan.
| | | | | | | |
Collapse
|
42
|
Electrochemical detection of droplet contents in polystyrene microfluidic chip with integrated micro film electrodes. J Electroanal Chem (Lausanne) 2014. [DOI: 10.1016/j.jelechem.2014.05.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
|
43
|
Venancio-Marques A, Baigl D. Digital optofluidics: LED-gated transport and fusion of microliter-sized organic droplets for chemical synthesis. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2014; 30:4207-4212. [PMID: 24702022 DOI: 10.1021/la5001254] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Microdroplet-based organic syntheses have been developed as a valuable alternative to traditional bulk-based methods. However, unlike their water counterparts, organic microdroplets can prove challenging to manipulate. Here, we describe the first optical manipulation of discrete, nanoliter- to microliter-sized apolar droplets floating on a liquid surface to induce on-demand droplet fusion for organic synthesis. We demonstrate droplet transport on centimeter-scale distances at speeds of 0.1 to 1 mm·s(-1) with well-programmable, sequential or parallel, fusion events. Because our strategy is compatible with most usual hydrocarbon solvents, such droplets can be used as microcompartments for reagents. Organic reactions readily occur upon droplet fusion, as demonstrated with an ene reaction. With an LED as the sole power source, and without any fabrication step, optical setup, pump or electrode implementation, our method provides a robust and versatile way to place digital organic chemistry under optical control.
Collapse
Affiliation(s)
- Anna Venancio-Marques
- Ecole Normale Supérieure-PSL Research University , Department of Chemistry, 24 rue Lhomond, F-75005 Paris, France
| | | |
Collapse
|
44
|
Müller T, Ruggeri FS, Kulik AJ, Shimanovich U, Mason TO, Knowles TPJ, Dietler G. Nanoscale spatially resolved infrared spectra from single microdroplets. LAB ON A CHIP 2014; 14:1315-1319. [PMID: 24519414 DOI: 10.1039/c3lc51219c] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Droplet microfluidics has emerged as a powerful platform allowing a large number of individual reactions to be carried out in spatially distinct microcompartments. Due to their small size, however, the spectroscopic characterisation of species encapsulated in such systems remains challenging. In this paper, we demonstrate the acquisition of infrared spectra from single microdroplets containing aggregation-prone proteins. To this effect, droplets are generated in a microfluidic flow-focussing device and subsequently deposited in a square array onto a ZnSe prism using a micro stamp. After drying, the solutes present in the droplets are illuminated locally by an infrared laser through the prism, and their thermal expansion upon absorption of infrared radiation is measured with an atomic force microscopy tip, granting nanoscale resolution. Using this approach, we resolve structural differences in the amide bands of the spectra of monomeric and aggregated lysozyme from single microdroplets with picolitre volume.
Collapse
Affiliation(s)
- Thomas Müller
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK.
| | | | | | | | | | | | | |
Collapse
|
45
|
Jeong HH, Noh YM, Jang SC, Lee CS. Droplet-based Microfluidic Device for High-throughput Screening. KOREAN CHEMICAL ENGINEERING RESEARCH 2014. [DOI: 10.9713/kcer.2014.52.2.141] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
46
|
Maddala J, Rengaswamy R. Design of multi-functional microfluidic ladder networks to passively control droplet spacing using genetic algorithms. Comput Chem Eng 2014. [DOI: 10.1016/j.compchemeng.2013.09.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
|
47
|
Liu P, Zhang J, Ferguson CN, Chen H, Loo JA. Measuring protein-ligand interactions using liquid sample desorption electrospray ionization mass spectrometry. Anal Chem 2013; 85:11966-72. [PMID: 24237005 PMCID: PMC3901310 DOI: 10.1021/ac402906d] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
We have previously shown that liquid sample desorption electrospray ionization-mass spectrometry (DESI-MS) is able to measure large proteins and noncovalently bound protein complexes (to 150 kDa) (Ferguson et al., Anal. Chem. 2011, 83, 6468-6473). In this study, we further investigate the application of liquid sample DESI-MS to probe protein-ligand interactions. Liquid sample DESI allows the direct formation of intact protein-ligand complex ions by spraying ligands toward separate protein sample solutions. This type of "reactive" DESI methodology can provide rapid information on binding stiochiometry, selectivity, and kinetics, as demonstrated by the binding of ribonuclease A (RNaseA, 13.7 kDa) with cytidine nucleotide ligands and the binding of lysozyme (14.3 kDa) with acetyl chitose ligands. A higher throughput method for ligand screening by liquid sample DESI was demonstrated, in which different ligands were sequentially injected as a segmented flow for DESI ionization. Furthermore, supercharging to enhance analyte charge can be integrated with liquid sample DESI-MS, without interfering with the formation of protein-ligand complexes.
Collapse
Affiliation(s)
- Pengyuan Liu
- Department of Chemistry and Biochemistry, University of California-Los Angeles, Los Angeles, California 90095, United States
- Center for Intelligent Chemical Instrumentation, Department of Chemistry and Biochemistry, Ohio University, Athens, Ohio 45701, United States
| | - Jiang Zhang
- Department of Chemistry and Biochemistry, University of California-Los Angeles, Los Angeles, California 90095, United States
| | - Carly N. Ferguson
- Department of Chemistry and Biochemistry, University of California-Los Angeles, Los Angeles, California 90095, United States
| | - Hao Chen
- Center for Intelligent Chemical Instrumentation, Department of Chemistry and Biochemistry, Ohio University, Athens, Ohio 45701, United States
| | - Joseph A. Loo
- Department of Chemistry and Biochemistry, University of California-Los Angeles, Los Angeles, California 90095, United States
- Department of Biological Chemistry, David Geffen School of Medicine, University of California-Los Angeles, Los Angeles, California 90095, United States
| |
Collapse
|
48
|
Aebisher D, Bartusik D, Liu Y, Zhao Y, Barahman M, Xu Q, Lyons AM, Greer A. Superhydrophobic photosensitizers. Mechanistic studies of (1)O2 generation in the plastron and solid/liquid droplet interface. J Am Chem Soc 2013; 135:18990-8. [PMID: 24295210 DOI: 10.1021/ja410529q] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
We describe here a physical-organic study of the first triphasic superhydrophobic sensitizer for photooxidations in water droplets. Control of synthetic parameters enables the mechanistic study of "borderline" two- and three-phase superhydrophobic sensitizer surfaces where (1)O2 is generated in compartments that are wetted, partially wetted, or remain dry in the plastron (i.e., air layer beneath the droplet). The superhydrophobic surface is synthesized by partially embedding silicon phthalocyanine (Pc) sensitizing particles to specific locations on polydimethylsiloxane (PDMS) posts printed in a square array (1 mm tall posts on 0.5 mm pitch). In the presence of red light and oxygen, singlet oxygen is formed on the superhydrophobic surface and reacts with 9,10-anthracene dipropionate dianion (1) within a freestanding water droplet to produce an endoperoxide in 54-72% yields. Control of the (1)O2 chemistry was achieved by the synthesis of superhydrophobic surfaces enriched with Pc particles either at the PDMS end-tips or at PDMS post bases. Much of the (1)O2 that reacts with anthracene 1 in the droplets was generated by the sensitizer "wetted" at the Pc particle/water droplet interface and gave the highest endoperoxide yields. About 20% of the (1)O2 can be introduced into the droplet from the plastron. The results indicate that the superhydrophobic sensitizer surface offers a unique system to study (1)O2 transfer routes where a balance of gas and liquid contributions of (1)O2 is tunable within the same superhydrophobic surface.
Collapse
Affiliation(s)
- David Aebisher
- Department of Natural Sciences, Shorter University , Rome, Georgia 30165, United States
| | | | | | | | | | | | | | | |
Collapse
|
49
|
Benz C, Retzbach H, Nagl S, Belder D. Protein-protein interaction analysis in single microfluidic droplets using FRET and fluorescence lifetime detection. LAB ON A CHIP 2013; 13:2808-2814. [PMID: 23674080 DOI: 10.1039/c3lc00057e] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Herein, we demonstrate the feasibility of a protein-protein interaction analysis and reaction progress monitoring in microfluidic droplets using FRET and microscopic fluorescence lifetime measurements. The fabrication of microdroplet chips using soft- and photolithographic techniques is demonstrated and the resulting chips reliably generate microdroplets of 630 pL and 6.71 nL at frequencies of 7.9 and 0.75 Hz, respectively. They were used for detection of protein-protein interactions in microdroplets using a model system of Alexa Fluor 488 labelled biotinylated BSA, Alexa Fluor 594 labelled streptavidin and unlabelled chicken egg white avidin. These microchips could be used for quantitative detection of avidin and streptavidin in microdroplets in direct and competitive assay formats with nanomolar detection limits, corresponding to attomole protein amounts. Four droplets were found to be sufficient for analytical determination. Fluorescence intensity ratio and fluorescence lifetime measurements were performed and compared for microdroplet FRET determination. A competitive on-chip binding assay for determination of unlabelled avidin using fluorescence lifetime detection could be performed within 135 s only.
Collapse
Affiliation(s)
- Christian Benz
- Institut für Analytische Chemie, Universität Leipzig, Johannisallee 29, Leipzig, Germany
| | | | | | | |
Collapse
|
50
|
Minardi CS, Taghioskoui M, Jang SJ, Jorabchi K. Reagent delivery by partial coalescence and noncoalescence of aqueous microdroplets in oil. Anal Chem 2013; 85:6491-6. [PMID: 23758450 DOI: 10.1021/ac4010524] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Reagent delivery constitutes a key step for reaction initiation in droplet-in-oil microfluidic platforms. Currently, this function is performed by complete fusion of a reagent droplet with the reactor droplet. The full coalescence, however, constrains the lower limit of volume delivery because reproducible droplet generation becomes exceedingly difficult as the reagent droplet volume is decreased. Here, we demonstrate fractional volume delivery based on partially coalescent and noncoalescent droplet collisions as a new reagent delivery mechanism. A charged reagent droplet is generated by pulsing a flow carrying needle to high voltage. The charged droplet is directed toward a grounded reactor droplet. Upon collision, the reagent droplet inverts its charge and is pulled away from the reactor droplet prior to full fusion, injecting only a fraction of its volume. The undelivered portion of the reagent drop is then merged with a collector droplet. We demonstrate that a wide range of fractional injections (0.003%-56%) can be reproducibly achieved, providing a means for minute volume delivery without small drop generation.
Collapse
Affiliation(s)
- Carina S Minardi
- Department of Chemistry, Georgetown University, Washington, D.C. 20057, USA
| | | | | | | |
Collapse
|