Fluorescence quenching for chloramphenicol detection in milk based on protein-stabilized Au nanoclusters

In the present study, we report a simple and rapid method for sensitive and selective determination of chloramphenicol (CAP) based on fluorescence of bovine serum albumin-stabilized Au nanoclusters (BSA-AuNCs). The BSA-AuNCs exhibit strong red emission. Upon addition of CAP to BSA-AuNCs, the fluorescence intensity of AuNCs shows a dramatic decrease attributing to the photo-induced electron transfer process from the electrostatically attached CAP to the BSA-AuNCs. The effects of pH, amount of BSA-AuNCs, temperature and reaction time on the detection of chloramphenicol were investigated. Under the optimal conditions, trace amounts of CAP could be detected. The linear working range is 0.10-70.00 μM with a detection limit 33 nM (S/N=3). In addition, the proposed method has been successfully applied to the detection of CAP in milk samples and largely improves the application of spectral method for quantitative analysis of CAP.