Surface-Enhanced Raman Scattering-Active Gold-Decorated Silicon Nanowire Substrates for Label-Free Detection of...

Area of Science:

• Nanotechnology and Materials Science
• Analytical Chemistry
• Biomedical Sensing

Background:

• Bilirubin (BR) is a hemoglobin breakdown product; elevated levels indicate liver disorders and can cause jaundice.
• High unconjugated BR in newborns leads to toxic levels, causing neurological damage (kernicterus).
• Accurate, fast, and sensitive BR detection is critical for timely diagnosis and treatment.

Purpose of the Study:

• To develop a novel surface-enhanced Raman scattering (SERS)-active substrate for sensitive, label-free bilirubin detection.
• To utilize gold-decorated silicon nanowires (Au@SiNWs) as a SERS platform for bilirubin sensing.

Main Methods:

• Synthesized silicon nanowires (SiNWs) via gold-assisted chemical etching.
• Decorated SiNWs with gold nanoparticles to create Au@SiNWs for SERS.
• Modified Au@SiNW surfaces with amino groups for enhanced bilirubin adsorption and detection.

Main Results:

• Demonstrated excellent SERS sensitivity with a model analyte (4-mercaptopyridine) down to 10^-8 M.
• Achieved label-free bilirubin detection with high reproducibility and a detection limit of 10^-6 M using amino-modified Au@SiNWs.
• Validated sensor performance in artificial urine, showing signal stability for 7 days at 5 × 10^-5 M BR.

Conclusions:

• Au@SiNWs represent a promising SERS-active substrate for sensitive and reproducible bilirubin detection.
• The developed sensor meets the sensitivity requirements for clinical applications.
• This technology can aid in reducing diagnostic time for bilirubin-related conditions.