Cerium(iii)-directed assembly of glutathione-capped gold nanoclusters for sensing and imaging of alkaline phosphatase-mediated hydrolysis of adenosine triphosphate

Abstract

Aggregation-induced emission enhancement (AIEE) of thiolated gold nanoclusters (AuNCs) has emerged as an attractive and alternative strategy to improve their brightness. This study demonstrates Ce(iii)-triggered AIEE of glutathione-capped AuNCs (GSH-AuNCs) through the coordination between two carboxylic groups of GSH and Ce(iii). The cluster size and valence state of GSH-AuNCs are almost identical to those of a Ce(iii)-induced assembly of GSH-AuNCs (named Ce(iii)-GSH-AuNCs). More importantly, the as-prepared Ce(iii)-GSH-AuNCs exhibit a higher quantum yield (up to 13%), longer luminescence lifetime, and shorter maximum luminescence peak than GSH-AuNCs. Additionally, Ce(iii)-GSH-AuNCs possess redox-switchable luminescence, high salt stability, and long-term storage stability. These findings provide clear evidence that the Ce(iii)-triggered aggregation of GSH-AuNCs is a crucial factor to improve the luminescence property of GSH-AuNCs. Intriguingly, the presence of adenosine triphosphate (ATP) switches off the luminescence of Ce(iii)-GSH AuNCs through the significant formation of Ce(iii)-ATP complexes. Furthermore, the ATP-induced luminescence quenching of Ce(iii)-GSH-AuNCs can be paired with the alkaline phosphatase (ALP)-ATP system to design a turn-on luminescent probe for ALP; the limit of detection for ALP is estimated to be 0.03 U L-1. Also, the biocompatibility of Ce(iii)-GSH-AuNCs enables the proposed system to detect ALP in human serum and HeLa cells.

Glutathione Disulfide as a Reducing, Capping, and Mass-Separating Agent for the Synthesis and Enrichment of Gold Nanoclusters

“…However, the luminescence intensities of the GSH-protected AuNCs obtained under both continuous and intermittent heating modes were weaker ( Figure 2 , traces R2 and R3). The absolute QY for GSH–AuNCs obtained under optimal conditions was determined to be 1.8%, which was similar to the reported values, i.e., 1% [ 40 ], 2% [ 41 , 42 ], and 1.2% [ 11 ]. In contrast, the GSSG–AuNCs possessed significantly higher luminescent efficacy, offering an absolute QY of 4.1%.…”

Gold(I)‐Thiolate Oligomers for Catalytic Hydrogenation of Nitroaromatics in Aqueous and Organic Medium

“…You et al. reported that the XPS spectrum of GSH−Au(I) complexes, obtained from the direct mixing of GSH and HAuCl 4 , exhibited a peak corresponding to Au(I) with a binding energy of 84.1 eV . By fitting the Au 4f 7/2 peak of the AuSO spectrum with the same binding energy, the AuSOs were suggested to consist of almost 100 % Au(I) (Figure H).…”

Capsulation of AuNCs with AIE Effect into Metal–Organic Framework for the Marriage of a Fluorescence and Colorimetric Biosensor to Detect Organophosphorus Pesticides

“…Among the fluorescent probes, gold nanoclusters (AuNCs) have attracted great attention in biosensing and biomedicine due to its facile synthesis and good biocompatibility. − However, the luminous performance of AuNCs is far inferior to those of the developed fluorophores (quantum dots, for instance), and their quantum yield rarely exceeds 0.1% . Therefore, studies have centered on enhancing the performance of AuNCs and explaining the mechanism of their luminescence.…”