A copper ion-mediated on-off-on gold nanocluster for pyrophosphate sensing and bioimaging in cells.
Anal Chim Acta 2023;
1249:340923. [PMID:
36868766 DOI:
10.1016/j.aca.2023.340923]
[Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Accepted: 01/30/2023] [Indexed: 02/09/2023]
Abstract
Herein, gold nanoclusters (AuNCs@EW@Lzm, AuEL) with the bright red fluorescence at 650 nm were prepared by egg white and lysozyme as double protein ligands, which exhibited good stability and high biocompatibility. The probe displayed highly selective detected pyrophosphate (PPi) based on Cu2+-mediated AuEL fluorescence quenching. Specifically, the fluorescence of AuEL was quenched once the Cu2+/Fe3+/Hg2+ is added to chelate with amino acids on the AuEL surface, respectively. Interestingly, the fluorescence of quenched AuEL-Cu2+ was significantly recovered by PPi, but not the other two. This phenomenon was attributed to the stronger bond between PPi and Cu2+ than that of Cu2+ with AuEL nanoclusters. The results demonstrated a good linear relationship between PPi concentration and the relative fluorescence intensity of AuEL-Cu2+ in the range of 131.00-685.40 μM with a detection limit of 2.56 μM. In addition, the quench AuEL-Cu2+ system can also be recovered in acidic environments (pH ≤ 5). And the as-synthesized AuEL showed excellent cell imaging and target the nucleus. Thus the fabrication of AuEL offers a facile strategy for efficient PPi assay and offers the potential for drug/gene delivery to the nucleus.
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