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Electrochemical/visual dual-readout aptasensor for Ochratoxin A detection integrated into a miniaturized paper-based analytical device
- Source :
- Biosensorsbioelectronics. 180
- Publication Year :
- 2021
-
Abstract
- Development of portable, sensitive and reliable devices for Ochratoxin A (OTA) detection is highly demanded, especially for resource-limited regions. Herein, a novel paper-based analytical device (PAD) is designed through wax printing and screen-printed technologies, which integrates sample flowing, electrode modification, cleaning and electrochemical (EC)/colorimetric signal output. To greatly enhance the detection sensitivity, we synthesized a chitosan functionalized MoS2–Au@Pt (Ch-MoS2-Au@Pt) via electrostatic self-assembly, and used it to immobilize the label aptamer (apta2) for signal regulation and amplification. Concretely, with the addition of analytes, the Ch-MoS2-Au@Pt-apta2 could be combined on the sensing interface by specific biorecognition and catalyzed reduction of H2O2, resulting in a remarkable EC response. Meanwhile, the released hydroxyl radicals (·OH) flowed to the visualization zone and promoted the oxidation of 3,3′,5,5′-tetramethylbenzidine for colorimetric detection. Consequently, the dual-mode PAD achieved acceptable prediction and accurate analysis in the range of 0.1–200 ng mL−1 and 1 × 10−4-200 ng mL−1 by matching the visual and EC signal intensity, respectively. Compared with traditional single-mode sensor for OTA, the proposed dual-mode aptasensor featuring independent signal conversion and readout, not only avoided the false-positive signal associated with detection condition and operation, but also enlarged the detection ranges and improved the sensitivity. Furthermore, the consistency of EC/colorimetric assay was validated in real OTA samples. Overall, this work provided a portable, cost-effective, sensitive and visualized aptasensor platform, which could be extended to various other mycotoxins in the field of food safety.
- Subjects :
- Ochratoxin A
Analyte
Materials science
Aptamer
Biomedical Engineering
Biophysics
Biosensing Techniques
Electrochemistry
Signal
chemistry.chemical_compound
Limit of Detection
business.industry
General Medicine
Paper based
Electrochemical Techniques
Hydrogen Peroxide
Aptamers, Nucleotide
Ochratoxins
chemistry
Electrode
Optoelectronics
Gold
business
Sensitivity (electronics)
Biotechnology
Subjects
Details
- ISSN :
- 18734235
- Volume :
- 180
- Database :
- OpenAIRE
- Journal :
- Biosensorsbioelectronics
- Accession number :
- edsair.doi.dedup.....226e11a4889c2007027a3b9f2bc96d5f