Highly sensitive chemiluminescence sensing system for organophosphates using mimic LDH supported ZIF-8 nanocomposite

Developing a new detection system for reliable recognition of threatening organophosphate poisons (OPs) is a challenging subject for analysts to control their undesirable effects. Here, a sensitive analytical assay for OPs was reported based on the high mimetic behavior of layered double hydroxides supported ZIF-8 nanocomposite (LDH@ZIF-8). The well-known inhibiting effect of OP analytes on the enzymatic activity of acetylcholinesterase (AChE) was exerted to gain a suitable selectivity. Following that, efficient chemiluminescence (CL) system assisted by LDH@ZIF-8 was employed to monitor the variation in the amount of produced H₂O₂. It is found that the synthesized LDH@ZIF-8 possess a high effective peroxidase-like activity and can remarkably enhance the emission of the ultra-weak rhodamine B (RhoB)-H₂O₂ CL reaction. More studied was done using fluorometric to ratify the mimetic properties of LDH@ZIF-8 nanocomposite. The high catalytic effect of developed nanocomposite assured the high efficacy of the CL system to detect the small changes in H₂O₂ concentration, resulting in a high sensitivity in the detection of OPs. The low-priced and simple synthesized LDH@ZIF-8 catalyst, as well as a simple and easy-to-use CL system can be beneficial in the development of an on-site and portable detection tools. A wide linear range of 0.5–300 nM was achieved for the determination of diazinon (as a model OP), and the detection limit was as low as 0.22 nM. The method showed high reproducibility and was reassured by its application for the analysis of environmental samples.