Luminol chemiluminescence catalysed by colloidal platinum nanoparticles

Area of Science:

• Nanomaterials Science
• Analytical Chemistry
• Electrochemistry

Background:

• Chemiluminescence (CL) systems, like luminol-hydrogen peroxide, are valuable analytical tools.
• Enhancing CL intensity and reproducibility is crucial for sensitive detection.
• Platinum nanoparticles (Pt NPs) are known catalysts with potential applications in CL enhancement.

Purpose of the Study:

• To investigate the effect of platinum colloids on the luminol-hydrogen peroxide chemiluminescence system.
• To synthesize and characterize citrate-protected platinum colloids for CL enhancement.
• To explore the mechanism behind Pt NP-enhanced CL and its application in determining analytes.

Main Methods:

• Synthesis of platinum colloids using hexachloroplatinic acid reduction with citrate and stabilizers.
• Characterization of platinum colloids using transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS).
• Measurement of chemiluminescence intensity using the luminol-H(2)O(2)-Pt colloid system.

Main Results:

• Citrate-protected platinum colloids significantly enhanced luminol-H(2)O(2) chemiluminescence.
• The most intense and reproducible CL signals were achieved with citrate as both reductant and stabilizer.
• TEM and XPS studies suggested catalytic activity of Pt NPs in accelerating electron transfer and radical generation.
• The system demonstrated applicability for determining uric acid, ascorbic acid, phenols, and amino acids.

Conclusions:

• Platinum nanoparticles catalyze the luminol-hydrogen peroxide reaction, leading to enhanced chemiluminescence.
• Citrate-protected platinum colloids provide an effective and reproducible method for CL enhancement.
• The luminol-H(2)O(2)-Pt colloid system shows promise for sensitive determination of various biologically and environmentally relevant compounds.