The Effect of Capping Agents on Gold Nanostar Stability, Functionalization, and Colorimetric Biosensing Capability

Area of Science:

• Nanotechnology
• Biochemistry
• Analytical Chemistry

Background:

• Capping agents are essential for nanoparticle stabilization.
• These agents can alter the surface chemistry and properties of gold nanostars (AuNS).
• This modification affects the performance of AuNS-based biosensors.

Purpose of the Study:

• To investigate how different capping agents influence the stability and functionality of AuNS.
• To evaluate the impact of capping agents on AuNS-based biosensors for hydrogen peroxide (H2O2) detection.
• To provide insights into selecting appropriate capping agents for enzyme-conjugated AuNS applications.

Main Methods:

• Synthesis and characterization of capped and bioconjugated AuNS with various capping agents.
• Application of AuNS as localized surface plasmon resonance (LSPR)-based H2O2 sensors.
• Enzyme immobilization using glucose oxidase (GOx) as a model enzyme.

Main Results:

• Various capping agents demonstrated distinct effects on AuNS stability, functionality, and biocatalysis.
• The choice of capping agent influenced the colorimetric readouts and overall sensor performance.
• Capped and bioconjugated AuNS showed varying degrees of efficacy in H2O2 sensing.

Conclusions:

• Capping agents play a critical role in determining the properties and performance of AuNS biosensors.
• The selection of capping agents directly impacts the stability and downstream applications of enzyme-conjugated AuNS.
• These findings offer guidance for optimizing AuNS-based sensor design and development.