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BIOPHOSENS: Carbon nanomaterials based electrochemical biosensor for detection of highly toxic organophosphate pesticides
Polish Academy of Sciences, Institute of Physical Chemistry, Kasprzaka 44/52, Warszawa 01-224, Poland
Title: Disposable sensor for organophosphate detection in drinking water"
Programme: ERA-NET MATERA+, Call 2009, May 2011 - December 2013,
Project aim and framework
Organophosphate pesticides are very popular in agriculture and industry due to their insecticidal activity . Pesticides are one of the most important pollutants, because of their accumulation in the environment and their high toxicity. They affect our health, attack neurological systems and even cause death. Therefore, the monitoring of the concentration of pesticides in drinking water is mandated by the EU.
This project is aimed to the construction of low-cost disposable biosensors for the monitoring of organophosphate pesticides in water, to substitute the time consuming chromatographic techniques used till date. Its main objectives are (i) to build suitable matrices to immobilise cholinesterase enzymes into screen printed electrodes (ii) to prepare low-cost polymeric electrodic supports for this bio-composite matrices (iii) to obtain long- life sensors where the enzyme is immobilised in the working electrode in optimum conditions, without leakage, and permitting a reproducible response to organophosphate pesticide detection.
Within the framework of this project our team constructed, characterised and tested new carbon nanomaterials based electrochemical biosensor for detection of highly toxic organophosphate pesticides. In construction we explored the fact that organophosphate pesticides toxicity results from the inhibition of the enzyme - acethylcholinesterase. This enzyme is capable to produce tiocholine from acetylthiocholine and the concentration of the product of this reaction marks enzyme activity. Thiocholine can be electrochemically oxidised and nanostructured electrodes provide favourable conditions for this reaction and good affinity to enzyme immobilization.
Organophosphate pesticide biosensor architecture based carbon nanomaterials (nanoparticles, nanotubes) were prepared by the layer-by-layer method. A conductive film is created by several alternate immersion of the substrate into suspensions of oppositely charged carbon nanoparticles and silicate submicroparticles or single walled carbon nanotubes. This substrate significantly decrease the overpotential of thiocholine oxidation. The effect of the amount of deposited material on the catalytic properties toward thiocholine oxidation is demonstrated. We have found the superiority of the sol-gel processed functionalised silicate matrix for the enzyme immobilisation. We will demonstrate the response of the sensor on different organophosphate pesticides like malathion, phosmet, dichlorovos; its stability; reproducibility; and detection limit.
Other partners are working on the transfer of this technology to screen printed electrodes.
Selected results were already presented during international conferences. At the moment patent application is prepared. After its submission preparation of 2 manuscripts to international electrochemical/analytical journals is planned. The obtained results will be a significant part of PhD Thesis.
Presentation: Polish Research Projects at Nano and Advanced Materials Workshop and Fair, by Marcin Opallo
See On-line Journal of Nano and Advanced Materials Workshop and Fair
Submitted: 2013-07-18 15:11 Revised: 2013-07-30 13:38