Gold Nanoplates for a Localized Surface Plasmon Resonance-Based Boric Acid Sensor

Area of Science:

• Nanotechnology
• Analytical Chemistry
• Materials Science

Background:

• Localized surface plasmon resonance (LSPR) in metallic nanostructures is highly sensitive to the surrounding dielectric environment.
• This sensitivity makes nanostructures promising for chemical sensing applications, including the detection of food contaminants like boric acid.

Purpose of the Study:

• To synthesize gold nanoplates with controlled shapes.
• To investigate the use of these gold nanoplates as a sensing material for detecting boric acid in aqueous solutions.
• To analyze the correlation between LSPR properties and boric acid concentration.

Main Methods:

• Seed-mediated growth method was employed to synthesize gold nanoplates of various shapes.
• Characterization of nanoplates' optical properties, specifically transverse (t-SPR) and longitudinal (l-SPR) surface plasmon resonance bands.
• Exposure of gold nanoplates to aqueous solutions with varying concentrations of boric acid and monitoring of LSPR band shifts.

Main Results:

• Gold nanoplates exhibited distinct t-SPR and l-SPR bands at 545 nm and 710 nm, respectively.
• The intensity and peak centers of both t-SPR and l-SPR bands changed upon interaction with boric acid.
• A linear correlation was observed between the changes in LSPR bands and the concentration of boric acid.

Conclusions:

• Gold nanoplates are effective sensing materials for detecting boric acid.
• The observed LSPR shifts provide a quantitative measure of boric acid concentration.
• This LSPR-based approach offers a promising method for sensitive and selective detection of boric acid in food safety applications.