Surface enhanced Raman Spectroscopy (SERS) Substrates

Surface Enhanced Raman Spectroscopy (SERS) is a technique that amplifies the Raman signal of a molecule when it is near a nanostructured metal surface typically gold or silver. The enhancement arises from localised surface plasmon resonance at the nanoparticle surface, enabling detection of trace analytes at concentrations far below what standard Raman spectroscopy can achieve.

Gold substrates perform well at longer excitation wavelengths (785 nm and 830 nm) and are well-suited to forensic, pharmaceutical, and narcotics applications. Silver substrates offer stronger enhancement at shorter wavelengths (532 nm and 785 nm) and are often preferred for analytes with lower intrinsic Raman cross-sections. If you are unsure which substrate is right for your application, contact the Nikalyte team for guidance.

Chemically synthesised colloidal nanoparticles carry hydrocarbon and ligand contaminants on their surface, which introduce background signal and reduce sensitivity. Nikalyte nanoparticles are fabricated in vacuum using a gas aggregation technique, producing ultra-pure, hydrocarbon-free particles with more free surface bonds available to bind the target analyte. Unlike colloidal solutions, which require liquid handling unsuitable for field conditions, Nikalyte substrates are paper-based, apply your sample and measure immediately, no preparation required.

Published application data covers fentanyl, fentanyl HCl, heroin, amphetamine sulfate, MDMA, caffeine, BPE, acetaminophen, naproxen, amoxicillin, and melamine. For analytes not listed, contact us to discuss whether existing data is available or whether custom testing is possible.

Yes. Nikalyte gold SERS substrates have been validated for fentanyl analog detection in street drug samples using the Agilent Resolve handheld Raman analyser, with results published in collaboration with Agilent Technologies. The paper-based substrate format requires no liquid handling, no drying, and no laboratory infrastructure, making it suitable for use by border control, police forces, and first responders.

The substrates have been validated with the Agilent Resolve and Wasatch Photonics compact Raman systems at 532 nm, 785 nm, and 830 nm excitation. They are compatible with any Raman instrument operating at these wavelengths. Contact Nikalyte if you need confirmation of compatibility with your specific system.

Nikalyte SERS substrates amplify Raman signals from 10³ to 10⁹ compared to standard Raman methods, enabling detection at parts-per-billion (ppb) levels. Limits of detection vary by analyte and excitation wavelength. Application notes for specific analytes are available on this page, and the team can provide further data on request.

Apply your analyte solution directly to the substrate surface and measure immediately, no drying step is required. The paper-based format is straightforward to handle in both laboratory and field conditions without specialist training or equipment. Substrates are supplied in packs of five and are available to order directly from the online shop.

Yes. Nikalyte’s R&D team offers bespoke SERS coatings for specific analytes or substrate formats. Contact the team at sales@nikalyte.com to discuss your requirements.

Online shop orders require a minimum of 5 packs. For formal quotations, the minimum is 10 packs, to request please mail sales@nikalyte.com. Both gold and silver substrates are available via the shop.