Development of Fe-N-C single-atom nanozymes assisted aptasensor for the detection of acetamiprid in water samples

Acetamiprid (Ace), extensively employed in agricultural production as a substitute for organophosphorus pesticides, poses a potential threat to the environment and human health due to excessive residues. Hence, the development of reliable and convenient techniques to determine Ace levels in the environment holds significant importance. Among various assay methods, nanomaterial-based aptamer-based biosensors (aptasensors) have emerged as efficient and promising tools. In this study, we successfully developed a novel aptasensor for monitoring Ace in the environmental water, utilizing advanced nanomaterials known as Fe-N-C single-atom nanozymes (SAzymes). Fe-N-C SAzymes exhibited excellent catalytic activity, high stability, and complete atom utilization. A facile dual-confinement route was employed for the synthesis of Fe-N-C SAzymes, and their performance as oxidase-like nanozymes was investigated. The synthesized Fe-N-C SAzymes presented distinct oxidase-like activity and demonstrated the capability to interact with a chromogenic indicator-TMB, serving as the signal transduction element in our assay. Furthermore, we found that thiol-modified aptamers could effectively dampen the oxidase-like activity of Fe-N-C SAzymes.Therefore, we successfully developed a Fe-N-C SAzymes assisted detection method for Ace, which exhibited high sensitivity (LOD = 16.9 nM) and selectivity. Overall, this work provides new insights into the design of multifunctional Fe-N-C SAzymes for environmental and biological applications.