Photoinduced Electron Transfer-Triggered g-C3N4\Rhodamine B Sensing System for the Ratiometric Fluorescence Quantitation of Carbendazim

Assays for carbendazim (Car) with high sensitivity and on-site screening have been urgently required to protect the ecosystem and prevent disease. In this work, a simple, sensitive, and reliable sensing system based on photoinduced electron transfer was established to detect carbendazim utilizing ultrathin graphitic carbon nitride (g-C3N4) nanosheets and rhodamine B (RB). Carbendazim reacts with g-C3N4 by electrostatic interactions to form pi-pi stacking, and the quenching of the blue fluorescence is caused by electron transfer. While RB works as a reference fluorescence sensor without any fluorescence change, leading to obvious ratiometric fluorescence variation from blue to purple. Under optimal conditions, a favorable linear range from 20 to 180 nM was obtained, with a low detection limit of 5.89 nM. In addition, a portable smartphone sensing platform was successfully used for carbendazim detection in real samples with excellent anti-interference capability, demonstrating the potential applications of carbendazim monitoring.

Automated summary

High sensitivity and on-site screening assays for carbendazim have been urgently required to protect the ecosystem and prevent disease. In this study, a simple, sensitive, and reliable sensing system based on photoinduced electron transfer was established using ultrathin graphitic carbon nitride nanosheets and rhodamine B. The system demonstrated a favorable linear range from 20 to 180 nM and a low detection limit of 5.89 nM, with a portable smartphone sensing platform successfully detecting carbendazim in real samples, showing potential applications for carbendazim monitoring.