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 Au8 nanocluster (Au8NC) for aflatoxin B1 (AFB1) detection was fabricated due to its strong carcinogenic and mutagenic effect on humans. The prepared polymer-Au8NC nanospheres displayed bright luminescence and good stability in aqueous solution. The obtained AFB1 fluorescent strip immunosensor achieved quantitative point-of-care detection of AFB1 in less than 15 min, with high selectivity and detection limits down to 0.27 ng/mL. In addition, the recovery rates of AFB1 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 AFB1, but also expanded the bio-applications of atomic-precise metal clusters.

Atomic-precise Pt2Cu4 cluster-based fluorescent sensor for rapid interleukin-6 detection.

Levonorgestrel protected Pt2Cu4 clusters were assembled with a polymer to prepare nanobeads (NBs) with intense red fluorescence. An immunofluorescence sensor based on Pt2Cu4NBs was established for the rapid and sensitive detection of interleukin-6 (IL-6) owing to its significance in inflammatory diseases, with a limit of detection of 42.66 pg mL-1. IL-6 spiked in serum was also accurately detected.