Bioconjugation of a Near-Infrared DNA-Stabilized Silver Nanocluster to Peptides and Human Insulin by Copper-Free Click Chemistry

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DNA-stabilized silver nanoclusters (DNA-AgNCs) are biocompatible emitters with intriguing properties. However, they have not been extensively used for bioimaging applications due to the lack of structural information and hence predictable conjugation strategies. Here, a copper-free click chemistry method for linking a well-characterized DNA-AgNC to molecules of interest is presented. Three different peptides and a small protein, human insulin, were tested as labeling targets. The conjugation to the target compounds was verified by MS, HPLC, and time-resolved anisotropy measurements. Moreover, the spectroscopic properties of DNA-AgNCs were found to be unaffected by the linking reactions. For DNA-AgNC-conjugated human insulin, fluorescence imaging studies were performed on Chinese hamster ovary (CHO) cells overexpressing human insulin receptor B (hIR-B). The specific staining of the CHO cell membranes demonstrates that DNA-AgNCs are great candidates for bioimaging applications, and the proposed linking strategy is easy to implement when the DNA-AgNC structure is known.

Original languageEnglish
JournalJournal of the American Chemical Society
Volume145
Issue number30
Pages (from-to)16771–16777
Number of pages7
ISSN0002-7863
DOIs
Publication statusPublished - 2023

Bibliographical note

Funding Information:
V.R., M.B.L., C.C., and T.V. acknowledge funding from the Villum Foundation (VKR023115) and the Independent Research Fund Denmark (0136-00024B). N.K.M., K.K.S., and K.J.J. thank the Villum Foundation (VKR18333) for funding the Biomolecular Nanoscale Engineering Center (BioNEC), a VILLUM center of excellence, and the Novo Nordisk Foundation funding for the Center for Biopharmaceuticals and Biobarriers in Drug Delivery (BioDelivery; Grand Challenge Program; NNF16OC0021948). The authors would like to thank Morten Lundh from Gubra for providing the CHO cells expressing the hIR-B.

Publisher Copyright:
© 2023 The Authors. Published by American Chemical Society.

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