Wasatch Photonics and Nikalyte Partner to advance applications of SERS

13 Jan 2022

Novel SERS substrate to detect materials, with apps in narcotics, food, bio, and environmental.

Wasatch Photonics and Nikalyte have announced a partnership to evaluate and test a novel SERS substrate for trace detection of materials, with applications in narcotics, food safety, pharmaceuticals, environmental, and biological analysis.

Surface Enhanced Raman Spectroscopy (SERS) is a specialized form of Raman spectroscopy in which the analyte of interest interacts with gold or silver nanostructures to enhance the Raman signal. It enables Raman spectroscopy, a technique most often used for the identification of bulk materials, to be applied to the detection of trace quantities of potentially harmful or biologically relevant compounds.

Nikalyte, a developer of nanoparticle coating equipment and services, has developed a new form of substrate for SERS analysis. It incorporates the ease of use of a solid SERS substrate with the reproducibility of liquid SERS at a cost-effective price point, thus overcoming previous limitations to widespread use of the SERS technique.

Conventional wet-deposited SERS substrates offer convenient sample preparation in that they employ an absorbent pad mounted to a microscope slide, but often display significant spatial inhomogeneities, resulting in low signal reproducibility. SERS using colloidal gold nanoparticles in aqueous solution, in contrast, yield very reproducible signals, but require handling of solutions that is not conducive to field use by non-experts.

The Nikalyte SERS substrate approach utilizes gold nanoparticles generated and deposited in vacuum, ensuring that they are ultra-pure and uniformly distributed. As no chemicals are used in the synthesis of the nanoparticles, the SERS substrates are free of contamination, delivering superior sensitivity and specificity. Nikalyte says these substrates are available for less than $10 at test quantities, and can be scaled for volume use.

SERS evaluation

The partners are evaluating the performance of these new SERS substrates for use in a variety of relevant applications. Wasatch manufactures high sensitivity, field-portable Raman spectrometers at wavelengths spanning 248-1064 nm, and says it is “well-positioned to evaluate the performance of the SERS substrates”.

The use of 785 nm and 830 nm excitation has been assessed for trace detection of a representative drug analyte, demonstrating a 1000x increase in the limit of detection using the Nikalyte SERS substrates. The results of this study are published here. Future work will focus on improving the limit of detection further, and on studies of other analytes relevant for promising SERS applications.

”Surface enhanced Raman is an exciting and rapidly growing field,” commented Dr Vicky Broadley, Nikalyte Sales and Marketing Director. “We are excited to be working with Wasatch Photonics to evaluate and develop our SERS technology and to push the limits of what current SERS sensors can offer.”

Surface Enhanced Raman Spectroscopy (SERS) using gold nanoparticles. (Image courtesy of Nikalyte Ltd.)