Gold nanostars as a colloidal substrate for in-solution SERS measurements using a handheld Raman spectrometer

Area of Science:

• Analytical Chemistry
• Nanotechnology
• Spectroscopy

Background:

• Raman spectroscopy advancements, including enhanced Raman intensities, have improved its analytical utility.
• Surface-Enhanced Raman Scattering (SERS) is crucial for low detection limits and quantitative analysis.
• In-solution SERS measurements are less explored compared to solid substrates.

Purpose of the Study:

• Optimize gold nanostar (AuNS) synthesis for colloidal SERS substrates.
• Develop in-solution SERS measurements using handheld instrumentation.
• Quantitate methimazole in urine samples.

Main Methods:

• Investigated buffer types and concentrations for AuNS synthesis.
• Evaluated SERS intensity based on surface coverage and aggregation.
• Developed a quantitative method for methimazole in urine.

Main Results:

• SERS intensity is maximized by conditions promoting higher probe surface coverage and AuNS aggregation.
• Optimized AuNS synthesis yields effective colloidal SERS substrates.
• Successfully quantified methimazole in urine using the developed method.

Conclusions:

• Water-dispersible SERS substrates combined with handheld instrumentation offer rapid and sensitive analytical capabilities.
• Optimized AuNS are suitable for in-solution SERS applications.
• This approach facilitates portable and efficient chemical analysis.