Dhull_2018_Environ.Technol__1

In present study, a biosensor was developed for detection of organophosphorous compounds. Core electrode of working electrode was obtained by depositing paste of Gold nanoparticles and Multi Walled Carbon Nanotubes on gold wire. The acetylcholinesterase enzyme was immobilized on carboxylated Single Walled Carbon Nanotubes and pasted onto core of electrode followed by coating with nafion layer to prevent enzyme leaching from electrode. This electrode was further used as working electrode in the sensor. This sensor worked on AChE inhibition mechanism where signal is inversely proportional to the amount of organophosphorous compounds. The electrocatalytic activity of this sensor was observed at potential of +0.360 mV. The standardized conditions for this sensor were observed as; pH at 7.0, temperature at 30 degrees C, and response time less than 10s. The linear working range of this biosensor was 0.1microM-130microM with lowest detection limit (LOD) of 1.9 nM, 2.3 nM, 2.2 nM and 2.5 nM for Methyl Parathion, Monocrotophos, Chlorpyrifos and Endosulfan respectively. The biosensor showed excellent reusability (upto 55 times) and can be stored stably for 2 months.