Affordable plasmonic biosensing: democratizing SERS with scalable, field-compatible substrate fabrication

Area of Science:

• Plasmonics
• Nanotechnology
• Biosensing

Background:

• Traditional surface-enhanced Raman spectroscopy (SERS) for point-of-care diagnostics faces challenges in cost, complexity, and reproducibility.
• Field deployment of SERS is hindered by the need for specialized equipment and stable, reliable substrates.

Purpose of the Study:

• To develop a democratized, cost-effective fabrication kit for SERS substrates.
• To enable local production of sensitive and reproducible biosensors using readily available materials and simple electrochemistry.

Main Methods:

• Utilized a low-cost fabrication kit ($39.54) with common materials and battery-powered electrochemistry.
• Leveraged commercially available bottled water for substrate fabrication.
• Demonstrated detection using a digital SERS approach.

Main Results:

• Achieved high sensitivity and reproducibility in SERS substrate fabrication.
• Detected trace levels of pesticides (Thiram, Thiabendazole) down to 0.1 ppm.
• Successfully identified bacteria, including Escherichia coli and Bacillus subtilis.

Conclusions:

• The developed kit offers a cost-effective ($1.33¢ per test) and accessible method for producing field-deployable SERS biosensors.
• This innovation can advance point-of-care diagnostics in resource-restricted areas.
• Enables label-free, high-sensitivity detection for applications in public health and food safety.