Smartphone-assisted dual-mode turn-off-on red-emission AuNCs/WS2 FRET sensor for detection of carbendazim

The overuse of pesticides poses a significant threat to human health, driving the need for accurate and rapid strategies to identify various pesticides. A fluorescent nano-sensor (R-AuNCs@Aptamer) was developed by integrating an amino-modified carbendazim aptamer with red-colored gold nanoclusters (R-AuNCs). We subsequently engineered an aptamer-triggered turn-off-on Förster resonance energy transfer (FRET) platform, employing R-AuNCs@Aptamer in conjunction with tungsten disulfide nanosheets (WS 2 NS). In this setup, the carbendazim aptamer-stabilized red-emitting R-AuNCs (∼655 nm) served as the energy donor, while WS 2 NS acted as a fluorescence quencher. Upon the introduction of carbendazim, alterations in fluorescence intensity were monitored at 655 nm, facilitating the recognition of carbendazim. The resulting fluorescent nano-sensor displayed outstanding selectivity towards carbendazim, exhibiting a broad detection range of 0.1 to 1000 μg/L and remarkable sensitivity with a low limit of detection. It demonstrated reliability and practicality when applied to Notoginseng Radix et Rhizoma and Ginseng Radix et Rhizoma samples, with recoveries ranging from 90 % to 110 %. By changing the aptamer sequence, this sensor can be customized to detect different pollutants, exhibiting excellent tailorability and broad application potential.