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  • Label free aptasensor for ochratoxin A detection using polythiophene-3-carboxylic acid.

Label free aptasensor for ochratoxin A detection using polythiophene-3-carboxylic acid.

Talanta (2018-05-16)
H Zejli, K Yugender Goud, Jean Louis Marty
ABSTRACT

This work demonstrates the development of electrochemical aptasensor using ochratoxin A (OTA) aptamers. Different aptamer coupling strategies were tested using polythiophene-carboxylic acid (PT3C) and polypyrrole-3-carboxylic acid (PP3C). The best sensitivity was recorded by polythiophene-3-carboxylic acid (PT3C) on screen-printed carbon electrode (SPCE) to attain the direct detection of OTA. The quantification of OTA was achieved by using electrochemical impedance spectroscopy. A good dynamic range 0.125-2.5 ng ml-1 was obtained for OTA with limit of detection (LOD) 0.125 ng ml-1 and Limit of quantification (LOQ) 0.3 ng ml-1 respectively. The good reproducibility was recorded with RSD% of 3.68. The obtained straight line equation was y = 0.4061 × + 1.03, r = 0.99. For real sample applications, the developed aptasensors were demonstrated in coffee samples. The aptasensor displayed good recovery values in the range 88-89%, thus exhibited the effectiveness of proposed aptasensor for such complex matrices.

MATERIALS
Product Number
Brand
Product Description

Sigma-Aldrich
Pyrrole-3-carboxylic acid, ≥96%
Supelco
Ochratoxin B solution, ~10 μg/mL in acetonitrile, analytical standard
Sigma-Aldrich
3-Thiophenecarboxylic acid, 99%