NiCr2O4 nanozyme based portable sensor kit for on-site quantification of nerve agent mimic for environment monitoring

Nerve agents are among the most dangerous chemical known to the human being. On account of an incident by utilizing nerve agents, the fabrication of a cost-effective and ready-to-use device for the convenient identification of nerve agents is needed. Herein, we developed a easy-to-use, portable sensor kit based on NiCr2O4 artificial nanozyme mimic to quantify diethyl-chloro-phosphate (DCP). The synthesized NiCr2O4 artificial nanozyme showed good oxidase and peroxidase-like catalytic activity for the conversion of colorless tetramethylbenzidine (TMB) to bluish-green oxTMB. It is recognized that the presence of DCP can assist the oxidation of TMB due to the easy binding of DCP with the amine group of TMB and enhance the catalytic process. Therefore, this mechanism is utilized to fabricate a colorimetric sensor kit for naked-eye quantification of DCP, which gives yellowish color after interaction with oxTMB. Furthermore, the practicability of a portable sensor kit was performed for the quantification of DCP in soil and water samples, and results showed a detection limit of 15.4 nM (3 & sigma; method). Thus, the proposed portable sensor kit's naked eye detection paves the way for an affordable and practical platform for the easy-to-use, reliable, and quick colorimetric quantification of DCP for environment monitoring.

Automated summary

A portable sensor based on NiCr2O4 artificial nanozyme was developed for the quantification of diethyl-chloro-phosphate (DCP), a nerve agent. The sensor utilizes the binding ability of DCP with an amine compound to achieve colorimetric detection visible to the naked eye. Detection experiments conducted in soil and water samples showed a detection limit of 15.4 nM for DCP.