All in one: AIE-featured carbon dots with antibacterial activity for multivariate detection of Ag+, Hg2+ and BSA in real samples

Multiple trace heavy metal pollutants present a serious threat to both the environment and ecosystems, and their coexistence also affected the detection efficiency. Therefore, multi-mode responsive optical probes with versatile application prospects for optical sensing are highly desired. Here, yellow-emissive carbon dots (Y-CDs) with aggregation-induced emission (AIE) characteristics were fabricated via a hydrothermal approach, boasting a absolute quantum yield of 13.88% and a fluorescence lifetime of 8.55 μs. Leveraging the AIE behavior and quenching effect, Y-CDs were successfully achieved the multivariate detection of Ag + , Hg 2+ separately, and further realized cascade sensing BSA, with detection limits of 5.59 μM, 7.7 nM, and 0.9 μM respectively. Subsequently, a portable smartphone-based sensing platform was developed to facilitate rapid on-site analysis, and a logic gate was designed to expedite integration into intelligent devices. Furthermore, Y-CDs demonstrated remarkable antibacterial action via in vitro antibacterial assays, displaying significant inhibitory effects against both E. coli and S. aureus , providing the possibilities for testing in the food and medical fields with high standards of hygiene permits. With their exceptional multifunctional sensing capabilities, Y-CDs were expected holding extensive promising application prospects in the realm of real-time monitoring of environmental and food safety.