Aptamer-modified pencil graphite electrodes for the impedimetric determination of ochratoxin A

Gokce G., Ben Aissa S., Nemcekova K., Catanante G., Raouafi N., Marty J.

FOOD CONTROL, cilt.115, 2020 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 115
  • Basım Tarihi: 2020
  • Doi Numarası: 10.1016/j.foodcont.2020.107271
  • Dergi Adı: FOOD CONTROL
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, PASCAL, BIOSIS, CAB Abstracts, Food Science & Technology Abstracts, Index Islamicus, Veterinary Science Database
  • Sivas Cumhuriyet Üniversitesi Adresli: Evet

Özet

Ochratoxin A (OTA), a widespread food contaminant, is considered as one of the most hazardous mycotoxins commonly occurring in beer. Herein, we describe a novel impedimetric aptasensor based on Pencil Graphite Electrodes (PGE) for the analysis of OTA. Taking advantage of its affordability and high active surface area, a PGE was modified with a specific aptamer, to achieve sensitive detection of OTA. This strategy relies on the target-induced increase in the electron transfer resistance (R-ct) upon OTA recognition using ferro/ferricyanide as a redox probe. With the addition of OTA, the formation of OTA-aptamer complex resulted in an increase of Act. The change of R-ct strongly depends on OTA concentration, which is applied for mycotoxin quantification. An acceptable linear range was obtained from 0.1 to 2.0 ng mL(-1) with a very good limit of detection as low as 0,1 ng mL(-1). This simple-to-design aptasensor was successfully tested in spiked beer samples, with OTA concentrations in the range of 0.4-1.6 ng mL(-1), attesting a recovery percentage of 93.4 +/- 6.6%. It also showed a high level of stability and reproducibility thanks to the electro-grafting method via in-situ generation of 4-carboxyphenyl diazonium salts. This PGE-based platform is a versatile approach for the design of low-cost aptasensors for food safety control.