Fluorescence switch of gold nanoclusters stabilized with bovine serum albumin for efficient and sensitive detection of cysteine and copper ion in mice with Alzheimer's disease

Constructing a Facile Biocomputing Platform Based on Smart Supramolecular Hydrogel Film Electrodes with Immobilized Enzymes and Gold Nanoclusters

“…46 These results strongly support the hypothesis of Cu(II)-induced aggregation and EDTA-induced disaggregation of AuNCs in films, which further leads to fluorescence quenching/recovery. 51 This quenching/recovery process is very similar to the reported mechanism how Cu(II) ions act on AuNCs in the aqueous dispersion. 52 The fluorescent quenching behavior of Cu(II) on the Fmoc-FF/AuNCs/HRP films was studied at different pH values ranging from 4.0 to 9.0 (SI Figure S9, curve a).…”

“…Thus, the fluorescence quenching should be attributed to the coordination of Cu(II) with the films and the coordination-induced aggregation of AuNCs in the films. 50,51 Both the XPS and DLS results support the above possible mechanism. Compared with the Fmoc-FF/AuNCs/HRP film electrodes before immersion in Cu(II) solutions (SI Figure S7, curve a), an obvious peak due to Cu 2p 3/2 appeared at 933.8 eV after the films were dipped into a solution containing Cu(II) for 5 min (SI Figure S7, curve b), which indicated that the copper atoms were "adsorbed" into the films.…”

“…According to the SEM images, the addition of Cu­(II) had no significant impact on the self-assembled structure of the Fmoc-FF framework (Figure , panels A,B and D,E). Thus, the fluorescence quenching should be attributed to the coordination of Cu­(II) with the films and the coordination-induced aggregation of AuNCs in the films. , …”

A novel polypeptide-modified fluorescent gold nanoclusters for copper ion detection

“…The fluorescence properties of AuNCs can be adjusted by using appropriate ligands and biocompatible scaffolds 29 , 30 . Previous studies have shown AuNCs could be prepared using proteins, amino acids, peptides, thiols, nucleic acids and other biomolecules as ligands, which have a high degree of biocompatibility and can be used for interference-free detection of biological materials 31 – 34 .…”

Synthesis of highly stable fluorescent poly(methacrylic acid-co-itaconic)-protected silver nanoclusters and sensitive detection of Cu2+

“…12,13,18 Abnormal copper content may cause negative effects on human health and even serious diseases, such as Alzheimer's disease, Parkinson's disease, and motor neuron disease. 12,23,24 Therefore, it is more and more important to establish copper detection methods in related chemical and biological samples. Several techniques have been employed to detect Cu 2+ , such as dispersive liquid-liquid microextraction, liquid chromatography-mass spectrometry, UV-vis spectroscopy, and atomic absorption spectroscopy.…”