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Williamson P, Piskunen P, Ijäs H, Butterworth A, Linko V, Corrigan DK. Signal Amplification in Electrochemical DNA Biosensors Using Target-Capturing DNA Origami Tiles. ACS Sens 2023; 8:1471-1480. [PMID: 36914224 PMCID: PMC10152479 DOI: 10.1021/acssensors.2c02469] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/16/2023]
Abstract
Electrochemical DNA (e-DNA) biosensors are feasible tools for disease monitoring, with their ability to translate hybridization events between a desired nucleic acid target and a functionalized transducer, into recordable electrical signals. Such an approach provides a powerful method of sample analysis, with a strong potential to generate a rapid time to result in response to low analyte concentrations. Here, we report a strategy for the amplification of electrochemical signals associated with DNA hybridization, by harnessing the programmability of the DNA origami method to construct a sandwich assay to boost charge transfer resistance (RCT) associated with target detection. This allowed for an improvement in the sensor limit of detection by two orders of magnitude compared to a conventional label-free e-DNA biosensor design and linearity for target concentrations between 10 pM and 1 nM without the requirement for probe labeling or enzymatic support. Additionally, this sensor design proved capable of achieving a high degree of strand selectivity in a challenging DNA-rich environment. This approach serves as a practical method for addressing strict sensitivity requirements necessary for a low-cost point-of-care device.
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Affiliation(s)
- Paul Williamson
- Department of Biomedical Engineering, University of Strathclyde, Glasgow G1 1QE, United Kingdom
| | - Petteri Piskunen
- Biohybrid Materials, Department of Bioproducts and Biosystems, Aalto University, 00076 Aalto, Finland
| | - Heini Ijäs
- Biohybrid Materials, Department of Bioproducts and Biosystems, Aalto University, 00076 Aalto, Finland.,Ludwig-Maximilians-University, Geschwister-Scholl-Platz 1, 80539 Munich, Germany
| | - Adrian Butterworth
- Department of Biomedical Engineering, University of Strathclyde, Glasgow G1 1QE, United Kingdom
| | - Veikko Linko
- Biohybrid Materials, Department of Bioproducts and Biosystems, Aalto University, 00076 Aalto, Finland.,LIBER Center of Excellence, Aalto University, 00076 Aalto, Finland.,Institute of Technology, University of Tartu, Nooruse 1, 50411 Tartu, Estonia
| | - Damion K Corrigan
- Department of Biomedical Engineering, University of Strathclyde, Glasgow G1 1QE, United Kingdom.,Department of Pure & Applied Chemistry, Thomas Graham Building, University of Strathclyde, 295 Cathedral Street, Glasgow G1 1XL, United Kingdom
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Ma T, Grzȩdowski AJ, Doneux T, Bizzotto D. Redox-Controlled Energy Transfer Quenching of Fluorophore-Labeled DNA SAMs Enables In Situ Study of These Complex Electrochemical Interfaces. J Am Chem Soc 2022; 144:23428-23437. [PMID: 36516982 DOI: 10.1021/jacs.2c09474] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Interfaces modified by a molecular monolayer can be challenging to study, particularly in situ, requiring novel approaches. Coupling electrochemical and optical approaches can be useful when signals are correlated. Here we detail a methodology that uses redox electrochemistry to control surface-based fluorescence intensity for detecting DNA hybridization and studying the uniformity of the surface response. A mixed composition single-strand DNA SAM was prepared using potential-assisted thiol exchange with two alkylthiol-modified ssDNAs that were either labeled with a fluorophore (AlexaFluor488) or a methylene blue (MB) redox tag. A significant change in fluorescence was observed when reducing MB to colorless leuco-MB. In situ fluorescence microscopy on a single-crystal gold bead electrode showed that fluorescence intensity depended on (1) the potential controlling the oxidation state of MB, (2) the surface density of DNA, (3) the MB:AlexFluor488 ratio in the DNA SAM, and (4) the local environment around the DNA SAM. MB efficiently quenched AlexaFluor488 fluorescence. Reduction of MB showed a significant increase in fluorescence resulting from a decrease in quenching or energy transfer efficiency. Hybridization of DNA SAMs with its unlabeled complement showed a large increase in fluorescence due to MB reduction for surfaces with sufficient DNA coverage. Comparing electrochemical-fluorescence measurements to electrochemical (SWV) measurements showed an improvement in detection of a small fraction of hybridized DNA SAM for surfaces with optimal DNA SAM composition and coverage. Additionally, this coupled electrochemical redox-fluorescence microscopy method can measure the spatial heterogeneity of electron-transfer kinetics and the influence of the local interfacial environment.
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Affiliation(s)
- Tianxiao Ma
- AMPEL and Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, CanadaV6T1Z4
| | - Adrian Jan Grzȩdowski
- AMPEL and Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, CanadaV6T1Z4
| | - Thomas Doneux
- Chemistry of Surfaces, Interfaces and Nanomaterials (ChemSIN), Faculté des Sciences, Université libre de Bruxelles (ULB), Boulevard du Triomphe 2, CP 255, B-1050Bruxelles, Belgium
| | - Dan Bizzotto
- AMPEL and Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, CanadaV6T1Z4
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Detection of breast cancer-related point-mutations using screen-printed and gold-plated electrochemical sensor arrays suitable for point-of-care applications. TALANTA OPEN 2022. [DOI: 10.1016/j.talo.2022.100150] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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Ma T, Bizzotto D. Improved Thermal Stability and Homogeneity of Low Probe Density DNA SAMs Using Potential-Assisted Thiol-Exchange Assembly Methods. Anal Chem 2021; 93:15973-15981. [PMID: 34813297 DOI: 10.1021/acs.analchem.1c03353] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Methods for producing DNA SAM-based sensors with improved thermal stability and control over the homogeneity of low DNA probe density will enable advanced sensor development. The thermal stability of low-coverage DNA SAMs was studied for surfaces prepared using potential-assisted thiol exchange (Edep) and compared to DNA SAMs prepared without control over the substrate potential (OCPdep). Both surface preparation methods were studied using in situ fluorescence microscopy and electrochemistry with fluorophore or redox-modified DNA SAMs on a single-crystal gold bead electrode. Fluorescence microscopy showed that the influence of the underlying surface crystallography was important in both cases. The highest thermal stability was realized for square or rectangular surface atomic structure (e.g., surfaces from 110 to 100). The 111 and related surfaces were the least thermally stable. The low DNA coverage surfaces prepared by Edep had better thermal stability and higher DNA probe mobility as compared to OCPdep-prepared surfaces with the similar coverage. These results were correlated with methylene blue redox-tagged DNA probes, which directly measured the average DNA coverage. Both methods indicated that Edep DNA SAMs were more uniformly distributed across the electrode surface, while the surfaces prepared via OCPdep assembled into clusters with reduced mobility. The potential-assisted thiol-exchange approach to preparing low-coverage DNA SAMs was shown to quickly create modified surfaces that were consistent, had mobility characteristics which should yield superior DNA hybridization efficiencies, and having greater thermal stability which will translate into a longer shelf-life.
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Affiliation(s)
- Tianxiao Ma
- AMPEL, University of British Columbia, Vancouver V6T 1Z4, Canada.,Department of Chemistry, University of British Columbia, Vancouver V6T 1Z4, Canada
| | - Dan Bizzotto
- AMPEL, University of British Columbia, Vancouver V6T 1Z4, Canada.,Department of Chemistry, University of British Columbia, Vancouver V6T 1Z4, Canada
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