Beijing Researchers Leverage Femtosecond Laser Dynamics to Engineer High Precision SERS Substrates for Rapid Food Safety Screening

New femtosecond laser shaping technique creates high-sensitivity SERS substrates for rapid pesticide detection and trace biochemical analysis in food safety.

By: AXL Media

Published: Apr 29, 2026, 6:44 AM EDT

Source: Information for this report was sourced from EurekAlert!

A New Frontier in Molecular Fingerprint Detection

Surface-Enhanced Raman Scattering (SERS) has long been recognized for its ability to amplify the chemical signals of molecules by factors reaching into the billions. This revolutionary optical technique relies on highly localized electromagnetic fields, commonly referred to as "hot spots," to identify substances at nearly the single-molecule level. According to a study published in Light: Advanced Manufacturing, scientists led by Professor Lan Jiang have successfully engineered a multi-level substrate that enhances these signals by precisely modulating the structural morphology of the detection surface.

Harnessing Electron Dynamics for Ultrafast Precision

The fabrication process utilizes temporally shaped femtosecond lasers, which allow for unparalleled flexibility in material modification. By adjusting the time interval between double pulses, the Beijing Institute of Technology team effectively regulated how material electrons absorb energy on an ultrafast timescale. This technique, combined with laser-assisted chemical etching, enabled the continuous tuning of microlens curvature over a nearly 30-fold range. This level of control ensures that the resulting triple cross-scale structures are dimensionally ordered, providing a dense and predictable distribution of detection points.

The Role of Curvature in Electric Field Coupling

In a first-of-its-kind investigation, the research team explored how the physical curvature of a substrate influences its local electric field intensity. Their findings reveal that increasing the curvature promotes a significant accumulation of surface charges, which in turn strengthens the coupling between wide-range and localized electric fields. Through both simulations and physical experiments, the researchers demonstrated that as the structural complexity and curvature increase, the Raman spectral intensity follows suit, offering a more powerful tool for trace biochemical analysis.