DISPLAYING OF THE POTENTIOMETER DEVICE PERFORMANCE WITH ACETYLCHOLINESTERASE ENZYME BIOCATALYST ON ORGANOPHOSPHATE PESTICIDE SENSOR ELECTRODE
Mashuni (1*)- Halimahtussaddiyah Ritonga (1)- M Jahiding (2)- Fitri Handayani Hamid (1)

1Department of Chemistry, Halu Oleo University, Kendari, 93132, Indonesia
2Department of Physics, Halu Oleo University, Kendari, 93132, Indonesia

Abstract

Due to the large-scale use and high toxicity of pesticides, developing practical, sensitive, fast, and cost-effective pesticide detection sensors is very important. The potentiometer measurement method detects organophosphate pesticides (OPPs) by inhibiting the enzyme acetylcholinesterase (AChE) activity. This method was developed to determine three types of OPPs, namely chlorpyrifos, profenofos and diazinon, through AChE immobilization on Au electrodes covered with 115% (w/v) cellulose acetate (CA) and 25% (v/v) glutaraldehyde (GTA) membrane-coated Au electrodes. SEM showed that the CA/GTA membrane morphology had a smooth and lumpy surface, while the average diameter by 562.33 nm. The AChE biosensor based on a potentiometer as a pesticide detector showed inhibition values for chlorpyrifos pesticides of 14.44 to 73.08%, profenofos pesticides of 11.98 to 77.98%, and diazinon pesticides of 18.58 to 83.27% with each response time are 5 minutes. In addition, the CA/GTA membrane electrode has high sensitivity in the working concentration range of \(1 \times 10^{-9}\) to \(1.0 \mu g/L \) and a lower detection limit of \(1 \times 10^{-9} \mu g/L \) for profenofos and diazinon while \(1 \times 10^{-10} \mu g/L \) for chlorpyrifos. Using an AChE-based biosensor with a potentiometer is a susceptible device for efficient and fast detection of pesticide residues.

Keywords: acetylcholinesterase, organophosphate, sensor, potentiometer

Topic: Analytical Chemistry