Aprotinin Encapsulated Gold Nanoclusters: A Fluorescent Bioprobe with Dynamically Nuclear Targeting and Selective Detection of Trypsin and Heavy Metal

摘要： Fluorescence imaging has currently emerged as one of the most frequently used noninvasive imaging technology to selectively monitor biological processes in living systems. In past decades, gold nanoclusters (Au NCs) received increasing attraction because of their intrinsic fluorescence and their inherent biocompatibility. As a stabilizing and reducing agent, an abundant, sustainable and widely used polypeptide derived drug molecule, aprotinin (Ap) is selected for the synthesis of Au nanoclusters (Ap-Au NCs) due to characteristic bioactivity, excellent biocompatibility, biodegradability, nonallergenic character. Herein, Ap encapsulated Au NCs exhibiting desirable red fluorescence feature was facilely produced for the first time, which were subsequently used for cell imaging and detection of various analytes. Much interestingly, dynamically subcellular localization of Ap-Au NCs from the cytoplasm to the nucleus in Hela cells was observed. Afterward, it has shown the selective and quantitative detection of trypsin by using Ap encapsulated Au NCs. Lastly, Ap-Au NCs were readily used for detection of mercury and copper quantitatively. The photoluminescence of the Ap-Au NCs was quenched with the addition of metioned analytes. This study opens crucial insights on the integration of biomolecule with metal nanoclusters, also discusses a multifunctional nanomaterial platform for cell imaging, subcellular targeting, biosensing and drug delivery.