Ligand-Involved Chemiluminescence Using Gold Nanoclusters: Mechanistic Elucidation and Its Application for...

Area of Science:

• Biochemistry
• Nanotechnology
• Analytical Chemistry

Background:

• Traditional molecular chemiluminescence (CL) has limited photon yields.
• Existing nanomaterial probes (e.g., CdTe, perovskites) face stability and biocompatibility issues.
• Protein-engineered nanomaterials offer potential for improved CL probes.

Purpose of the Study:

• To develop a stable, biocompatible, and highly emissive CL probe using gold nanoclusters (Au NCs) stabilized by bovine serum albumin (BSA).
• To investigate the mechanism of CL emission and its dependence on BSA structure and oxidants.
• To establish a CL assay for sensitive detection of trypsin.

Main Methods:

• Fabrication of BSA-stabilized Au NCs (BSA-Au NCs) as CL probes.
• Investigation of CL intensity variations with BSA concentration and oxidants (NaClO vs. H2O2).
• Structural analysis (X-ray photoelectron spectroscopy) and spectral analysis to elucidate emission mechanism.
• Development of a signal-off CL assay for trypsin detection.

Main Results:

• BSA-Au NCs exhibited significantly higher CL intensity (~800-fold) with NaClO compared to H2O2.
• A loosely folded BSA secondary structure correlated with stronger CL emission.
• Ligand-involved emission mechanism was supported by spectral and XPS data.
• A sensitive signal-off CL assay for trypsin detection was achieved with a detection limit of 3.3 ng/mL.

Conclusions:

• BSA-Au NCs provide a robust, high-intensity CL probe overcoming limitations of traditional CL and other nanomaterials.
• The study elucidates the ligand-involved CL mechanism in BSA-Au NCs.
• This work enables the rational design of advanced Au nanocluster-based luminescent materials and sensitive biosensing platforms.