# High Sensitivity SERS Substrate with Femtosecond Laser-Printed Nanohole Arrays

## TL;DR

A new method creates highly sensitive and reproducible SERS substrates using laser-printed nanoholes and silver nanoparticles.

## Contribution

A novel fabrication method for SERS substrates with high sensitivity and reproducibility using femtosecond laser-printed nanohole arrays.

## Key findings

- Achieved a detection limit of 10−10 M for rhodamine 6G.
- Obtained enhancement factors up to 3.5 × 10⁴.
- Demonstrated 5.5% RSD at 1361 cm−1 peak, indicating high reproducibility.

## Abstract

This article presents a novel method for fabricating repeatable and uniform surface-enhanced Raman scattering (SERS) substrates. The proposed method consists of two steps: (1) the fabrication of nanohole arrays using advanced femtosecond laser-induced two-photon polymerization (TPP) technology; and (2) the deposition of 9 nm thick silver nanoparticles on the nanohole arrays. The proposed nanohole arrays were optimized at the diameter, and the thickness of the silver film at two parameters. Regarding SERS substrates, a limit of detection of 10−10 M (rhodamine 6G) and analytical enhancement factors up to 3.5 × 104 were achieved. At 1361 cm−1, the relative standard deviation (RSD) of the characteristic peak was 5.5%, demonstrating a highly reproducible SERS substrate.