Dual-emission fluorescence biosensing of vancomycin based on AIEgen–peptide conjugates and aptamer-modified Au nanoclusters

Precise doses of antibiotics are necessary to prevent bacterial drug resistance. Although fluorescent sensors are promising for quantitative analyses of antibiotics, improvements in feasibility, selectivity, and sensitivity are needed. In this study, a dual-emission fluorescence biosensor platform was developed for simple, selective, and sensitive determination of vancomycin (Van) based on a peptide conjugated with blue-emitting aggregation-induced emission luminogens (AIEgen) and aptamer-modified red-emitting gold nanoclusters (AuNCs-apt). The peptide and aptamer together recognized Van with high affinity, thus changing the fluorescence intensity at 470 nm and 650 nm, respectively. This platform displayed excellent linear correlation between the fluorescence response and a Van concentration ranging 0.01–100 μg mL⁻¹, and the limit of detection (LOD) was 2.79 ng mL⁻¹. In addition to the ability to accurately distinguish Van from glycopeptide antibiotics, the newly developed biosensor allowed for naked-eye detection of 1 μg mL⁻¹ Van. These results and those of serum samples and microdialysate samples support the application of this newly developed method for Van monitoring and clinical diagnosis.