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In-situ amplified voltammetric immunoassay for ochratoxin A by coupling a platinum nanocatalyst based enhancement to a redox cycling process promoted by an enzyme mimic.
- Source :
-
Microchimica Acta . Jul2017, Vol. 184 Issue 7, p2445-2453. 9p. - Publication Year :
- 2017
-
Abstract
- A new signal amplified protocol for sensitive monitor of ochratoxin A was developed by coupling platinum enhancement technique to a redox cycling amplification strategy. Initially, platinum-enclosed gold cores (AuPtNP) were functionalized with monoconal antibody against ochratoxin A (OTA) to act as signal tags. Upon addition of analyte (OTA), competitive immunobinding occurs between OTA and an OTA-BSA conjugate immobilized on a ferrocene modified electrode for the anti-OTA on the signal tags. Next, the AuPtNPs on the immunosensor are incubated with a platinum enhancing solution to initiate the growth of additional catalysts in order to further promote the catalytic cycling between p-aminophenol and p-quinoneimine with the aid of the reductant NaBH and ferrocene. As a result, the analytical signal is strongly enhanced and can be measured by differential pulse voltammetry in the range from −300 mV to 600 mV (vs. SCE) at 50 mV s. Under optimized conditions, the immunosensor displays a dynamic working range that extends from 0.2 pg⋅mL to 5 ng⋅mL of OTA, with a lower detection limit of 75 fg⋅mL. The method is highly selective and was applied to the determination of OTA in (spiked) red wine samples. [ABSTRACT FROM AUTHOR]
- Subjects :
- *VOLTAMMETRY
*IMMUNOASSAY
*OCHRATOXINS
*PLATINUM catalysts
*PLATINUM nanoparticles
Subjects
Details
- Language :
- English
- ISSN :
- 00263672
- Volume :
- 184
- Issue :
- 7
- Database :
- Academic Search Index
- Journal :
- Microchimica Acta
- Publication Type :
- Academic Journal
- Accession number :
- 123518866
- Full Text :
- https://doi.org/10.1007/s00604-017-2223-2