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Chandrasekharan HK, Wlodarczyk KL, MacPherson WN, Maroto-Valer MM. In-situ multicore fibre-based pH mapping through obstacles in integrated microfluidic devices. Sci Rep 2024; 14:2839. [PMID: 38310119 PMCID: PMC10838297 DOI: 10.1038/s41598-024-53106-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2023] [Accepted: 01/27/2024] [Indexed: 02/05/2024] Open
Abstract
Microfluidic systems with integrated sensors are ideal platforms to study and emulate processes such as complex multiphase flow and reactive transport in porous media, numerical modeling of bulk systems in medicine, and in engineering. Existing commercial optical fibre sensing systems used in integrated microfluidic devices are based on single-core fibres, limiting the spatial resolution in parameter measurements in such application scenarios. Here, we propose a multicore fibre-based pH system for in-situ pH mapping with tens of micrometer spatial resolution in microfluidic devices. The demonstration uses custom laser-manufactured glass microfluidic devices (called further micromodels) consisting of two round ports. The micromodels comprise two lintels for the injection of various pH buffers and an outlet. The two-port system facilitates the injection of various pH solutions using independent pressure pumps. The multicore fibre imaging system provides spatial information about the pH environment from the intensity distribution of fluorescence emission from the sensor attached to the fibre end facet, making use of the cores in the fibre as independent measurement channels. As proof-of-concept, we performed pH measurements in micromodels through obstacles (glass and rock beads), showing that the particle features can be clearly distinguishable from the intensity distribution from the fibre sensor.
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Affiliation(s)
- Harikumar K Chandrasekharan
- Applied Optics and Photonics Group, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh, EH14 4AS, UK.
| | - Krystian L Wlodarczyk
- Applied Optics and Photonics Group, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh, EH14 4AS, UK
- Research Centre for Carbon Solutions (RCCS), School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh, EH14 4AS, UK
| | - William N MacPherson
- Applied Optics and Photonics Group, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh, EH14 4AS, UK
| | - M Mercedes Maroto-Valer
- Research Centre for Carbon Solutions (RCCS), School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh, EH14 4AS, UK
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Coliaie P, Prajapati A, Ali R, Boukerche M, Korde A, Kelkar MS, Nere NK, Singh MR. In-line measurement of liquid-liquid phase separation boundaries using a turbidity-sensor-integrated continuous-flow microfluidic device. LAB ON A CHIP 2022; 22:2299-2306. [PMID: 35451445 DOI: 10.1039/d1lc01112j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Liquid-liquid phase separation (LLPS), also known as oiling-out, is the appearance of the second liquid phase preceding the crystallization. LLPS is an undesirable phenomenon that can occur during the crystallization of active pharmaceutical ingredients (APIs), proteins, and polymers. It is typically avoided during crystallization due to its detrimental impacts on crystalline products due to lowered crystallization rate, the inclusion of impurities, and alteration in particle morphology and size distribution. In situ monitoring of phase separation enables investigating LLPS and identifying the phase separation boundaries. Various process analytical technologies (PATs) have been implemented to determine the LLPS boundaries prior to crystallization to prevent oiling out of compounds. The LLPS measurements using PATs can be time-consuming, expensive, and challenging. Here, we have implemented a fully integrated continuous-flow microfluidic device with a turbidity sensor to quickly and accurately evaluate the LLPS boundaries for a β-alanine, water, and IPA mixture. The turbidity-sensor-integrated continuous-flow microfluidic device is also placed under an optical microscope to visually track and record the appearance and disappearance of oil droplets. Streams of an aqueous solution of β-alanine, pure solvent (water), and pure antisolvent (IPA or ethanol) are pumped into the continuous-flow microfluidic device at various flow rates to obtain the compositions at which the solution becomes turbid. The onset of turbidity is measured using a custom-designed, in-line turbidity sensor. The LLPS boundaries can be estimated using the turbidity-sensor-integrated microfluidic device in less than 30 min, which will significantly improve and enhance the workflow of the pharmaceutical drug (or crystalline material) development process.
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Affiliation(s)
- Paria Coliaie
- Department of Chemical Engineering, University of Illinois Chicago, 929 W. Taylor St., Chicago, IL 60607, USA.
| | - Aditya Prajapati
- Department of Chemical Engineering, University of Illinois Chicago, 929 W. Taylor St., Chicago, IL 60607, USA.
| | - Rabia Ali
- Department of Chemical Engineering, University of Illinois Chicago, 929 W. Taylor St., Chicago, IL 60607, USA.
| | - Moussa Boukerche
- Center of Excellence for Isolation & Separation Technologies (CoExIST), Process R&D, AbbVie Inc., North Chicago, IL 60064, USA
| | - Akshay Korde
- Center of Excellence for Isolation & Separation Technologies (CoExIST), Process R&D, AbbVie Inc., North Chicago, IL 60064, USA
| | - Manish S Kelkar
- Center of Excellence for Isolation & Separation Technologies (CoExIST), Process R&D, AbbVie Inc., North Chicago, IL 60064, USA
| | - Nandkishor K Nere
- Department of Chemical Engineering, University of Illinois Chicago, 929 W. Taylor St., Chicago, IL 60607, USA.
- Center of Excellence for Isolation & Separation Technologies (CoExIST), Process R&D, AbbVie Inc., North Chicago, IL 60064, USA
| | - Meenesh R Singh
- Department of Chemical Engineering, University of Illinois Chicago, 929 W. Taylor St., Chicago, IL 60607, USA.
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