Green Synthesis of Gluten-Stabilized Fluorescent Gold Quantum Clusters: Application As Turn-On Sensing of Human Blood Creatinine

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 (Au_QC@gluten). Gluten, a cysteine-rich protein serves as an effective stabilizing agent for these clusters. The Au_QC@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, Au_QC@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 Au_QC@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

Recent Progress on Ligand-Protected Metal Nanoclusters in Photocatalysis

The reckless use of non-replenishable fuels by the growing population for energy and the resultant incessant emissions of hazardous gases and waste products into the atmosphere have insisted that scientists fabricate materials capable of managing these global threats at once. In recent studies, photocatalysis has been employed to focus on utilizing renewable solar energy to initiate chemical processes with the aid of semiconductors and highly selective catalysts. A wide range of nanoparticles has showcased promising photocatalytic properties. Metal nanoclusters (MNCs) with sizes below 2 nm, stabilized by ligands, show discrete energy levels and exhibit unique optoelectronic properties, which are vital to photocatalysis. In this review, we intend to compile information on the synthesis, true nature, and stability of the MNCs decorated with ligands and the varying photocatalytic efficiency of metal NCs concerning changes in the aforementioned domains. The review discusses the photocatalytic activity of atomically precise ligand-protected MNCs and their hybrids in the domain of energy conversion processes such as the photodegradation of dyes, the oxygen evolution reaction (ORR), the hydrogen evolution reaction (HER), and the CO2 reduction reaction (CO2RR)