Semiconducting Tungsten Trioxide Thin Films for High-Performance SERS Biosensors

Area of Science:

• Materials Science
• Nanotechnology
• Analytical Chemistry

Background:

• Surface-Enhanced Raman Scattering (SERS) offers high sensitivity but faces challenges with noble metal substrate biocompatibility and sustainability.
• Developing alternative SERS substrates is crucial for broader applications.

Purpose of the Study:

• To develop a novel, sustainable, and biocompatible semiconductor-based SERS platform.
• To achieve ultrasensitive detection surpassing conventional metal-based SERS systems.

Main Methods:

• Synthesis of ultrathin tungsten trioxide (WO3) nanofilms on fluorine-doped tin oxide (FTO) via annealing.
• Fabrication of WO3-gold nanoparticle (Au NP) composites for enhanced sensitivity.
• Utilizing Density Functional Theory (DFT) and band structure analysis to understand performance enhancement mechanisms.

Main Results:

• Achieved a high Raman enhancement factor of 1.36 × 10^6.
• Demonstrated ultrasensitive detection of rhodamine 6G (R6G) and methylene blue (MB) at ultralow concentrations.
• Successfully detected adenine molecules using WO3-Au NP composites, highlighting the role of plasmonic hot spots.

Conclusions:

• The WO3-based SERS platform provides a sustainable and high-performance alternative to noble metal substrates.
• Synergistic effects of interface charge transfer and oxygen vacancies enhance SERS performance.
• This technology paves the way for environmentally friendly and scalable Raman sensing applications.