1
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Irving OJ, Matthews L, Coulthard S, Neely RK, Grant MM, Albrecht T. Sterically Enhanced Control of Enzyme-Assisted DNA Assembly. Chembiochem 2023; 24:e202300361. [PMID: 37681318 DOI: 10.1002/cbic.202300361] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Revised: 08/15/2023] [Accepted: 09/06/2023] [Indexed: 09/09/2023]
Abstract
Traditional methods for the assembly of functionalised DNA structures, involving enzyme restriction and modification, present difficulties when working with small DNA fragments (<100 bp), in part due to a lack of control over enzymatic action during the DNA modification process. This limits the design flexibility and range of accessible DNA structures. Here, we show that these limitations can be overcome by introducing chemical modifications into the DNA that spatially restrict enzymatic activity. This approach, sterically controlled nuclease enhanced (SCoNE) DNA assembly, thereby circumvents the size limitations of conventional Gibson assembly (GA) and allows the preparation of well-defined, functionalised DNA structures with multiple probes for specific analytes, such as IL-6, procalcitonin (PCT), and a biotin reporter group. Notably, when using the same starting materials, conventional GA under typical conditions fails. We demonstrate successful analyte capture based on standard and modified sandwich ELISA and also show how the inclusion of biotin probes provides additional functionality for product isolation.
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Affiliation(s)
- Oliver J Irving
- School of Chemistry, University of Birmingham Edgbaston, Birmingham, B15 2TT, UK
| | - Lauren Matthews
- School of Chemistry, University of Birmingham Edgbaston, Birmingham, B15 2TT, UK
| | - Steven Coulthard
- School of Chemistry, University of Birmingham Edgbaston, Birmingham, B15 2TT, UK
| | - Robert K Neely
- School of Chemistry, University of Birmingham Edgbaston, Birmingham, B15 2TT, UK
| | - Melissa M Grant
- School of Dentistry, Institute of Clinical Sciences, University of Birmingham and Birmingham Dental Hospital, Birmingham Community Healthcare Trust), 5 Mill Pool Way, Edgbaston, Birmingham, B5 7EG, UK
| | - Tim Albrecht
- School of Chemistry, University of Birmingham Edgbaston, Birmingham, B15 2TT, UK
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2
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Roelen Z, Tabard-Cossa V. Synthesis of length-tunable DNA carriers for nanopore sensing. PLoS One 2023; 18:e0290559. [PMID: 37611030 PMCID: PMC10446168 DOI: 10.1371/journal.pone.0290559] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Accepted: 08/09/2023] [Indexed: 08/25/2023] Open
Abstract
Molecular carriers represent an increasingly common strategy in the field of nanopore sensing to use secondary molecules to selectively report on the presence of target analytes in solution, allowing for sensitive assays of otherwise hard-to-detect molecules such as small, weakly-charged proteins. However, existing carrier designs can often introduce drawbacks to nanopore experiments including higher levels of cost/complexity and carrier-pore interactions that lead to ambiguous signals and elevated clogging rates. In this work, we present a simple method of carrier production based on sticky-ended DNA molecules that emphasizes ease-of-synthesis and compatibility with nanopore sensing and analysis. In particular, our method incorporates the ability to flexibly control the length of the DNA carriers produced, enhancing the multiplexing potential of this carrier system through the separable nanopore signals they could generate for distinct targets. A proof-of-concept nanopore experiment is also presented, involving carriers produced by our method with multiple lengths and attached to DNA nanostructure targets, in order to validate the capabilities of the system. As the breadth of applications for nanopore sensors continues to expand, the availability of tools such as those presented here to help translate the outcomes of these applications into robust nanopore signals will be of major importance.
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Affiliation(s)
- Zachary Roelen
- Department of Physics, University of Ottawa, Ottawa, Ontario, Canada
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3
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Zheng X, Liu J, Li M, Hua Y, Liang X, Zhang S, Zhang X, Shao Y. Dual-Nanopipettes for the Detection of Single Nanoparticles and Small Molecules. Anal Chem 2022; 94:17431-17438. [PMID: 36495265 DOI: 10.1021/acs.analchem.2c03344] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Nanopore sensing is blooming due to its label-free and high sensitivity features. As a novel nanopore, a droplet is formed at the orifice of a dual-nanopipette, which allows for the translocation of analytes through the two channels at a relatively low speed and the promotion of signal-to-noise ratio. However, nanopore sensing based on the principle of current blockage requires the pore size to be comparable to that of the single entity, which poses a huge challenge for the direct detection of small molecules. In this work, gold nanoparticles (Au NPs) modified with sulfhydryl poly(ethylene glycol) (PEG-SH) or aptamers were detected successfully. The size difference of Au NPs and the interaction between Au NPs and dual-nanopipettes could be distinguished sensitively. Furthermore, Au NPs modified with designed aptamers will produce different blocking current after capturing the corresponding small molecules (e.g., dopamine and serotonin). Even non-electroactive ions, such as potassium ions, can also be detected, which is difficult to sense based on redox reactions, and further illustrates that the change of surface properties of nanoparticles is responsible for the detection. This work expands the application of nanopipette sensing for Au NPs and provides a universal platform for the small-molecule detection, which has the potential application in biosensing.
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Affiliation(s)
- Xinhe Zheng
- Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
| | - Junjie Liu
- Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
| | - Mingzhi Li
- Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
| | - Yutong Hua
- Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
| | - Xu Liang
- Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
| | - Shudong Zhang
- Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
| | - Xianhao Zhang
- Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
| | - Yuanhua Shao
- Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
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4
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Ren R, Sun M, Goel P, Cai S, Kotov NA, Kuang H, Xu C, Ivanov AP, Edel JB. Single-Molecule Binding Assay Using Nanopores and Dimeric NP Conjugates. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2021; 33:e2103067. [PMID: 34323323 DOI: 10.1002/adma.202103067] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Revised: 05/25/2021] [Indexed: 06/13/2023]
Abstract
The ability to measure biomarkers, both specifically and selectively at the single-molecule level in biological fluids, has the potential to transform the diagnosis, monitoring, and therapeutic intervention of diseases. The use of nanopores has been gaining prominence in this area, not only for sequencing but more recently in screening applications. The selectivity of nanopore sensing can be substantially improved with the use of labels, but substantial challenges remain, especially when trying to differentiate between bound from unbound targets. Here highly sensitive and selective molecular probes made from nanoparticles (NPs) that self-assemble and dimerize upon binding to a biological target are designed. It is shown that both single and paired NPs can be successfully resolved and detected at the single-molecule nanopore sensing and can be used for applications such as antigen/antibody detection and microRNA (miRNA) sequence analysis. It is expected that such technology will contribute significantly to developing highly sensitive and selective strategies for the diagnosis and screening of diseases without the need for sample processing or amplification while requiring minimal sample volume.
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Affiliation(s)
- Ren Ren
- Department of Chemistry, Molecular Science Research Hub, Imperial College London, White City Campus, 82 Wood Lane, London, W12 0BZ, UK
| | - Maozhong Sun
- Key Lab of Synthetic and Biological Colloids, Ministry of Education, State Key Lab of Food Science and Technology, International Joint Research Laboratory for Biointerface and Biodetection, School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu, 214122, P. R. China
| | - Pratibha Goel
- Department of Chemistry, Molecular Science Research Hub, Imperial College London, White City Campus, 82 Wood Lane, London, W12 0BZ, UK
| | - Shenglin Cai
- Department of Chemistry, Molecular Science Research Hub, Imperial College London, White City Campus, 82 Wood Lane, London, W12 0BZ, UK
| | - Nicholas A Kotov
- Department of Chemical Engineering, University of Michigan, Ann Arbor, MI, 48109, USA
- Department of Materials Science and Engineering, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Hua Kuang
- Key Lab of Synthetic and Biological Colloids, Ministry of Education, State Key Lab of Food Science and Technology, International Joint Research Laboratory for Biointerface and Biodetection, School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu, 214122, P. R. China
| | - Chuanlai Xu
- Key Lab of Synthetic and Biological Colloids, Ministry of Education, State Key Lab of Food Science and Technology, International Joint Research Laboratory for Biointerface and Biodetection, School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu, 214122, P. R. China
| | - Aleksandar P Ivanov
- Department of Chemistry, Molecular Science Research Hub, Imperial College London, White City Campus, 82 Wood Lane, London, W12 0BZ, UK
| | - Joshua B Edel
- Department of Chemistry, Molecular Science Research Hub, Imperial College London, White City Campus, 82 Wood Lane, London, W12 0BZ, UK
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5
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Luchian T, Mereuta L, Park Y, Asandei A, Schiopu I. Single-molecule, hybridization-based strategies for short nucleic acids detection and recognition with nanopores. Proteomics 2021; 22:e2100046. [PMID: 34275186 DOI: 10.1002/pmic.202100046] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Revised: 06/21/2021] [Accepted: 07/13/2021] [Indexed: 12/23/2022]
Abstract
DNA nanotechnology has seen large developments over the last 30 years through the combination of detection and discovery of DNAs, and solid phase synthesis to increase the chemical functionalities on nucleic acids, leading to the emergence of novel and sophisticated in features, nucleic acids-based biopolymers. Arguably, nanopores developed for fast and direct detection of a large variety of molecules, are part of a revolutionary technological evolution which led to cheaper, smaller and considerably easier to use devices enabling DNA detection and sequencing at the single-molecule level. Through their versatility, the nanopore-based tools proved useful biomedicine, nanoscale chemistry, biology and physics, as well as other disciplines spanning materials science to ecology and anthropology. This mini-review discusses the progress of nanopore- and hybridization-based DNA detection, and explores a range of state-of-the-art applications afforded through the combination of certain synthetically-derived polymers mimicking nucleic acids and nanopores, for the single-molecule biophysics on short DNA structures.
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Affiliation(s)
- Tudor Luchian
- Department of Physics, Alexandru I. Cuza University, Iasi, Romania
| | - Loredana Mereuta
- Department of Physics, Alexandru I. Cuza University, Iasi, Romania
| | - Yoonkyung Park
- Department of Biomedical Science and Research Center for Proteinaceous Materials (RCPM), Chosun University, Gwangju, Republic of Korea
| | - Alina Asandei
- Interdisciplinary Research Institute, Sciences Department, "Alexandru I. Cuza" University, Iasi, Romania
| | - Irina Schiopu
- Interdisciplinary Research Institute, Sciences Department, "Alexandru I. Cuza" University, Iasi, Romania
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6
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Chen K, Gularek F, Liu B, Weinhold E, Keyser UF. Electrical DNA Sequence Mapping Using Oligodeoxynucleotide Labels and Nanopores. ACS NANO 2021; 15:2679-2685. [PMID: 33478224 PMCID: PMC7905879 DOI: 10.1021/acsnano.0c07947] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Identifying DNA species is crucial for diagnostics. For DNA identification, single-molecule DNA sequence mapping is an alternative to DNA sequencing toward fast point-of-care testing, which traditionally relies on targeting and labeling DNA sequences with fluorescent labels and readout using optical imaging methods. A nanopore is a promising sensor as a complement to optical mapping with advantages of electric measurement suitable for portable devices and potential for high resolution. Here, we demonstrate a high-resolution nanopore-based DNA sequence mapping by labeling specific short sequence motifs with oligodeoxynucleotides (ODNs) using DNA methyltransferase (MTase) and detecting them using nanopores. We successfully detected ODNs down to the size of 11 nucleotides without introducing extra reporters and resolved neighboring sites with a distance of 141 bp (∼48 nm) on a single DNA molecule. To accurately locate the sequence motif positions on DNA, a nanopore data analysis method is proposed by considering DNA velocity change through nanopores and using ensemble statistics to translate the time-dependent signals to the location information. Our platform enables high-resolution detection of small labels on DNA and high-accuracy localization of them for DNA species identification in an all-electrical format. The method presents an alternative to optical techniques relying on fluorescent labels and is promising for miniature-scale integration for diagnostic applications.
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Affiliation(s)
- Kaikai Chen
- Cavendish
Laboratory, University of Cambridge, JJ Thomson Avenue, Cambridge CB3 0HE, United Kingdom
| | - Felix Gularek
- Institute
of Organic Chemistry, RWTH Aachen University, Landoltweg 1, D-52056 Aachen, Germany
| | - Boyao Liu
- Cavendish
Laboratory, University of Cambridge, JJ Thomson Avenue, Cambridge CB3 0HE, United Kingdom
| | - Elmar Weinhold
- Institute
of Organic Chemistry, RWTH Aachen University, Landoltweg 1, D-52056 Aachen, Germany
| | - Ulrich F. Keyser
- Cavendish
Laboratory, University of Cambridge, JJ Thomson Avenue, Cambridge CB3 0HE, United Kingdom
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7
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Rational design of DNA nanostructures for single molecule biosensing. Nat Commun 2020; 11:4384. [PMID: 32873796 PMCID: PMC7463249 DOI: 10.1038/s41467-020-18132-1] [Citation(s) in RCA: 66] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2020] [Accepted: 07/31/2020] [Indexed: 02/07/2023] Open
Abstract
The ability to detect low concentrations of biomarkers in patient samples is one of the cornerstones of modern healthcare. In general, biosensing approaches are based on measuring signals resulting from the interaction of a large ensemble of molecules with the sensor. Here, we report a biosensor platform using DNA origami featuring a central cavity with a target-specific DNA aptamer coupled with a nanopore read-out to enable individual biomarker detection. We show that the modulation of the ion current through the nanopore upon the DNA origami translocation strongly depends on the presence of the biomarker in the cavity. We exploit this to generate a biosensing platform with a limit of detection of 3 nM and capable of the detection of human C-reactive protein (CRP) in clinically relevant fluids. Future development of this approach may enable multiplexed biomarker detection by using ribbons of DNA origami with integrated barcoding.
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8
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Mereuta L, Asandei A, Dragomir IS, Bucataru IC, Park J, Seo CH, Park Y, Luchian T. Sequence-specific detection of single-stranded DNA with a gold nanoparticle-protein nanopore approach. Sci Rep 2020; 10:11323. [PMID: 32647249 PMCID: PMC7347621 DOI: 10.1038/s41598-020-68258-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2020] [Accepted: 06/22/2020] [Indexed: 12/13/2022] Open
Abstract
Fast, cheap and easy to use nucleic acids detection methods are crucial to mitigate adverse impacts caused by various pathogens, and are essential in forensic investigations, food safety monitoring or evolution of infectious diseases. We report here a method based on the α-hemolysin (α-HL) nanopore, working in conjunction to unmodified citrate anion-coated gold nanoparticles (AuNPs), to detect nanomolar concentrations of short single-stranded DNA sequences (ssDNA). The core idea was to use charge neutral peptide nucleic acids (PNA) as hybridization probe for complementary target ssDNAs, and monitor at the single-particle level the PNA-induced aggregation propensity AuNPs during PNA–DNA duplexes formation, by recording ionic current blockades signature of AuNP–α-HL interactions. This approach offers advantages including: (1) a simple to operate platform, producing clear-cut readout signals based on distinct size differences of PNA-induced AuNPs aggregates, in relation to the presence in solution of complementary ssDNAs to the PNA fragments (2) sensitive and selective detection of target ssDNAs (3) specific ssDNA detection in the presence of interference DNA, without sample labeling or signal amplification. The powerful synergy of protein nanopore-based nanoparticle detection and specific PNA–DNA hybridization introduces a new strategy for nucleic acids biosensing with short detection time and label-free operation.
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Affiliation(s)
- Loredana Mereuta
- Department of Physics, 'Alexandru I. Cuza' University, 700506, Iasi, Romania.
| | - Alina Asandei
- Sciences Department, Interdisciplinary Research Institute, 'Alexandru I. Cuza' University, 700506, Iasi, Romania
| | - Isabela S Dragomir
- Sciences Department, Interdisciplinary Research Institute, 'Alexandru I. Cuza' University, 700506, Iasi, Romania
| | - Ioana C Bucataru
- Department of Physics, 'Alexandru I. Cuza' University, 700506, Iasi, Romania
| | - Jonggwan Park
- Department of Bioinformatics, Kongju National University, Kongju, 32588, Republic of Korea
| | - Chang Ho Seo
- Department of Bioinformatics, Kongju National University, Kongju, 32588, Republic of Korea
| | - Yoonkyung Park
- Department of Biomedical Science and Research Center for Proteinaceous Materials (RCPM), Chosun University, Gwangju, 61452, Republic of Korea.
| | - Tudor Luchian
- Department of Physics, 'Alexandru I. Cuza' University, 700506, Iasi, Romania.
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9
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Asandei A, Mereuta L, Park J, Seo CH, Park Y, Luchian T. Nonfunctionalized PNAs as Beacons for Nucleic Acid Detection in a Nanopore System. ACS Sens 2019; 4:1502-1507. [PMID: 31119934 DOI: 10.1021/acssensors.9b00553] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
In this work, single-channel current recordings were used to selectively detect individual ssDNA strands in the vestibule of the α-hemolysin (α-HL) protein nanopore. The sensing mechanism was based on the detection of the intrinsic topological change of target ssDNA molecules after the hybridization with complementary PNA fragments. The readily distinguishable current signatures of PNA-DNA duplexes reversible association with the α-HL's vestibule, in terms of blockade amplitudes and kinetic features, allows specific detection of nucleic acid hybridization.
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Affiliation(s)
| | | | - Jonggwan Park
- Department of Bioinformatics, Kongju National University, Kongju, South Korea, 32588
| | - Chang Ho Seo
- Department of Bioinformatics, Kongju National University, Kongju, South Korea, 32588
| | - Yoonkyung Park
- Department of Department of Biomedical Science and Research Center for Proteinaceous Materials (RCPM), Chosun University, Gwangju, South Korea, 61452
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10
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Mereuta L, Asandei A, Schiopu I, Park Y, Luchian T. Nanopore-Assisted, Sequence-Specific Detection, and Single-Molecule Hybridization Analysis of Short, Single-Stranded DNAs. Anal Chem 2019; 91:8630-8637. [PMID: 31194518 DOI: 10.1021/acs.analchem.9b02080] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
We report here on the ability of the α-hemolysin (α-HL) nanopore to achieve label-free, selective, and real-time detection of 15 nt long ssDNA fragments in solution, by exploiting their hybridization with freely added, polycationic peptides-functionalized PNAs. At the core of our work lies the paradigm that when PNAs and ssDNA are mixed together, the bulk concentration of free PNA decreases, depending upon the (mis)match degree between complementary strands and their relative concentrations. We demonstrate that the ssDNA sensing principle and throughput of the method are determined by the rate at which nonhybridized, polycationic peptides-functionalized PNA molecules arrive at the α-HL's vestibule entrance and thread into the nanopore. We found that with the application of a 30-fold salt gradient across the nanopore, the method enhances single-molecule detection sensitivity in the nanomolar range of ssDNA concentrations. This study demonstrates that the transmembrane potential-dependent unzip of single PNA-DNA duplexes at the α-HL's β-barrel entry permits discrimination between sequences that differ by one base pair.
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Affiliation(s)
| | | | | | - Yoonkyung Park
- Department of Department of Biomedical Science and Research Center for Proteinaceous Materials (RCPM) , Chosun University , Gwangju 61452 , Republic of Korea
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11
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Albrecht T. Single-Molecule Analysis with Solid-State Nanopores. ANNUAL REVIEW OF ANALYTICAL CHEMISTRY (PALO ALTO, CALIF.) 2019; 12:371-387. [PMID: 30707594 DOI: 10.1146/annurev-anchem-061417-125903] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Solid-state nanopores and nanopipettes are an exciting class of single-molecule sensors that has grown enormously over the last two decades. They offer a platform for testing fundamental concepts of stochasticity and transport at the nanoscale, for studying single-molecule biophysics and, increasingly, also for new analytical applications and in biomedical sensing. This review covers some fundamental aspects underpinning sensor operation and transport and, at the same time, it aims to put these into context as an analytical technique. It highlights new and recent developments and discusses some of the challenges lying ahead.
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Affiliation(s)
- Tim Albrecht
- School of Chemistry, University of Birmingham, Birmingham B15 2TT, United Kingdom;
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12
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Small molecule electro-optical binding assay using nanopores. Nat Commun 2019; 10:1797. [PMID: 30996223 PMCID: PMC6470146 DOI: 10.1038/s41467-019-09476-4] [Citation(s) in RCA: 61] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Accepted: 03/12/2019] [Indexed: 01/12/2023] Open
Abstract
The identification of short nucleic acids and proteins at the single molecule level is a major driving force for the development of novel detection strategies. Nanopore sensing has been gaining in prominence due to its label-free operation and single molecule sensitivity. However, it remains challenging to detect small molecules selectively. Here we propose to combine the electrical sensing modality of a nanopore with fluorescence-based detection. Selectivity is achieved by grafting either molecular beacons, complementary DNA, or proteins to a DNA molecular carrier. We show that the fraction of synchronised events between the electrical and optical channels, can be used to perform single molecule binding assays without the need to directly label the analyte. Such a strategy can be used to detect targets in complex biological fluids such as human serum and urine. Future optimisation of this technology may enable novel assays for quantitative protein detection as well as gene mutation analysis with applications in next-generation clinical sample analysis. Nanopore detection of small molecules can be improved using molecular carriers, but separating a small analyte from the carrier signal can be challenging. Here the authors address this challenge using simultaneous electrical and optical readout in nanopore sensing to detect small molecules and quantify binding affinities.
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