A signal-on detection of organophosphorus pesticides by fluorescent probe based on aggregation-induced emission

Organophosphorus pesticides (OPs) have been broadly used in agriculture because of their high insecticidal efficiency. However, most OPs are highly toxic, since they can irreversibly inhibit acetylcholinesterase (AChE), leading to the neurotransmitter acetylcholine disorder which triggers a series of neurological diseases, and even death. Therefore, the rapid and sensitive detection of OPs is of great significance to life health and environmental protection. In this work, new derivatives of tetraphenylethene (TPE) with one or two aldehyde groups were synthesized and characterized, showing that they exhibited different aggregation-induced emission (AIE) effects in different pH solutions. Especially, the hydrolysis product of acetylthiocholine iodide (ATCh) catalyzed by acetylcholinesterase (AChE) can influence the pH of solution, causing the protonation of TPE-1 and changing its fluorescent intensity. Considering that the AChE activity can be specifically inhibited by OPs, the proposed TPE-1 was used to detect OPs between 0.009 and 22.5 mg/L with a detection limit of 0.008 mg/L. In addition, the selectivity was acceptable, providing a possible application for the detection of OPs.