Development of Au8 nanocluster-based fluorescent strip immunosensor for sensitive detection of aflatoxin B1

Gold clusters with intriguing chemical/physical properties have great promise in applications such as sensing and bio-imaging due to their fascinating photoluminescence character. In this study, an immunofluorescence sensor based on levonorgestrel protected atomically precise Au 8 nanocluster (Au 8 NC) for aflatoxin B 1 (AFB 1 ) detection was fabricated due to its strong carcinogenic and mutagenic effect on humans. The prepared polymer-Au 8 NC nanospheres displayed bright luminescence and good stability in aqueous solution. The obtained AFB 1 fluorescent strip immunosensor achieved quantitative point-of-care detection of AFB 1 in less than 15 min, with high selectivity and detection limits down to 0.27 ng/mL. In addition, the recovery rates of AFB 1 from tea soup ranged from 96% to 105% with relative standard deviations less than 10%. This work not only realized high-sensitively fluorescent sensing for AFB 1 , but also expanded the bio-applications of atomic-precise metal clusters.