Comparison of biosensoric and chromatographic methods for the detection of pesticides

Abstract

Screen-printed biosensors with immobilized acetylcholine esterase (AChE) were used for measuring fruit and vegetable samples that had first been analysed using gas and high-performance liquid chromatography. The output signal for the biosensors is the current, which is used to calculate relative inhibition (RI), a measured quantity. RI is proportional to the inhibiting (toxic) effect of organophosphates and carbamates. Measurements with AChE biosensors are not easily reproducible. This problem is solved by the choice of an arbitrary toxicity standard of 1.25 μM Syntostigmin. Measurements were evaluated by the ratio of the relative inhibition of the sample against the relative inhibition of Syntostigmin. Results obtained from the biosensor match those of chromatography in 19 out of 38 total measurements made and for nine out of 19 positive samples. The confirmation rate was 50%. Future work must check the limit of 0.1 and the independent control of inhibiting pesticides contents after measurements using the biosensor.

Keywords:

• Acetylcholine esterase
• Food analysis
• Enzyme-based biosensor

Acknowledgements

This research has been supported by the Research and Development Programme ANTOPE – Analyser of Toxicity of Pesticides granted by Czech Ministry of Industry registered by FD-K2/53.