Targeted antibacterial potency against multidrug resistance pathogen enhanced with N, S co-doped carbon quantum dots selectively recognizes rifampicin

A simple environment-friendly nitrogen, sulphur dual doped carbon quantum dots (N, S-CQDs) has been developed via a simple microwave-assisted method using mercaptosuccinic acid and diethylenetriamine. The interactions of the N, S-CQDs with various randomly chosen common commercial antibiotics were studied using their indigenous fluorescence properties. The N, S-CQDs were found to selectively interact with rifampicin over other tested antibiotics via the interaction between the accessible functional groups of N, S-CQDs and rifampicin resulting in loss of its fluorescence. The interaction of N, S-CQDs and rifampicin was tight and irreversible. Thus, the environmental exposure of free rifampicin, rifampicin-directed antimicrobial resistance among bacteria, and rifampicin toxicity might be mitigated in the future by the use of these N, S-CQDs. While tested on the HuH-7 human cell line, we found that the N, S-CQDs neither can kill nor impair the proliferation of the cells, indicating its non-cytotoxic nature. Furthermore, the quantum dot also possesses antimicrobial activity against both Gram-positive, and Gram-negative bacteria and their drug resistance varieties possibly by disrupting the cellular boundaries. N, S-CQDs could be effective next-generation antimicrobials for having synergistic nature when applied with other common antibiotics.