Protein
mediated syntheses of fluorescent noble metal quantum clusters
have proven to be particularly attractive owing to their high stability
and biocompatibility. Here, we present the cost-effective synthesis
of novel, water-soluble, and stable fluorescent gold quantum clusters
via a facile and green method using wheat gluten protein as a stabilizing
agent (AuQC@gluten). Gluten, a cysteine-rich protein serves
as an effective stabilizing agent for these clusters. The AuQC@gluten shows intense red emission at ∼680 nm and is characterized
using UV–vis spectroscopy, fluorescence, Fourier-transform
infrared spectroscopy (FT-IR), transmission electron microscopy (TEM),
and X-ray photoelectron spectroscopy (XPS). Contrary to any other
protein protected gold quantum cluster, AuQC@gluten is
highly stable toward reactive oxygen species like H2O2, revealing its promising application in biomedical fields
such as bioimaging, biolabeling, etc. The red emitting AuQC@gluten has been applied in the detection of creatinine with high
sensitivity and selectivity. The detection limit is found to be 2
nM in the linear range from 20 μM to 520 μM. This method
allows the accurate detection of creatinine in clinical blood samples,
indicating its promising biomedical applications.