Detection of Organophosphorus Pesticides with Colorimetry and Computer Image Analysis

Abstract

Organophosphorus pesticides (OPs) represent a very important class of pesticides that are widely used in agriculture because of their relatively high-performance and moderate environmental persistence, hence the sensitive and specific detection of OPs is highly significant. Based on the inhibitory effect of acetylcholinesterase (AChE) induced by inhibitors, including OPs and carbamates, a colorimetric analysis was used for detection of OPs with computer image analysis of color density in CMYK (cyan, magenta, yellow and black) color space and non-linear modeling. The results showed that there was a gradually weakened trend of yellow intensity with the increase of the concentration of dichlorvos. The quantitative analysis of dichlorvos was achieved by Artificial Neural Network (ANN) modeling, and the results showed that the established model had a good predictive ability between training sets and predictive sets. Real cabbage samples containing dichlorvos were detected by colorimetry and gas chromatography (GC), respectively. The results showed that there was no significant difference between colorimetry and GC (P > 0.05). The experiments of accuracy, precision and repeatability revealed good performance for detection of OPs. AChE can also be inhibited by carbamates, and therefore this method has potential applications in real samples for OPs and carbamates because of high selectivity and sensitivity.

Optimisation of a gold nanoparticle-based aptasensor integrated with image processing for the colorimetric detection of acephate using response surface methodology

“…However, their bulky size, complicated operating procedures, long operation time, and expensive analytical procedures justify the need for a simple, easy to operate, and affordable method that can be employed on site. Many sensors have been developed based on colorimetric [23][24][25] and electrochemical [26][27][28] detection methods for the detection of OPs. However, a rapid, sensitive, and selective method for an accurate detection of Ac remains highly desired.…”

Peroxidase-mimicking Activity of PCN-222(Fe) for Colorimetric Sensing of Acetylcholinesterase Activity and Inhibition

“…2,3 Irreversible inhibitors, such as chemical nerve agents, ultimately lead to asphyxiation. 4 The development of sensitive methods for detection of AChE activity and its inhibitors is thus crucial.…”

Modified Biosensor for Cholinesterase Inhibitors with Guinea Green B as the Color Indicator

“…Some cholinesterase inhibitors, especially nerve chemical warfare agents, are extremely toxic: for instance, the agents GB (sarin), GD (soman) and GF (cyclosarin) have LCt 50 by inhalation about 35 mg·min/m 3 , the agent VX even a mere 15 mg·min/m 3 . So, biosensors based on very sensitive enzymatic (cholinesterase) reactions are required for simple detection of the substances in dangerous concentrations [ 5 , 6 , 7 , 8 ].…”