Enhanced-sensitivity and rapid-response for the detection of kanamycin based on ethanol-assisted AIEE effect in silver-doped gold nanoclusters

In this study, a novel solvent-assisted strategy was developed for the rapid and sensitive detection of kanamycin (KAN) based on glutathione-capped silver-doped gold nanoclusters (AuAg NCs). Ethanol solvent played a key role in disrupting the hydration shell of metal(I)-thiolate complexes in AuAg NCs. KAN, as a specific linker between AuAg NCs through electrostatic interaction and metal-amine coordination, induced the formation of large aggregates and thus triggered prolonged photoluminescence lifetime as well as strong luminescence enhancement by restricting molecular motions in AuAg NCs. The KAN-stimulated turn-on principle allows AuAg NCs to exhibit 4-fold sensitivity in 40% ethanol/water (V/V) mixed solution compared to that in water. The improved aggregation-induced-emission enhancement (AIEE) feature endows the AuAg NCs with selective recognition for KAN and realizes rapid detection in a short response time of 60 s with a low detection limit of 8.6 nM. By integrating AuAg NCs with a Pasteur pipette, a facile sample-to-answer test kit for on-site determination with low cost and high efficiency was constructed, offering potential applications in the timely analysis of contaminants in environmental emergencies.