Nanoporous Copper Films as Platform for UV-SERS: Sensitivity and Ability to Perform Chiral Discrimination
Abstract
Surface enhanced Raman spectroscopy (SERS) in the ultraviolet (UV) region offers important advantages for biomolecular detection, including resonance enhancement and reduced fluorescence interference. However, the development of UV SERS substrates that combine low cost, reproducibility, and chemical stability remains challenging. Here, we employ a dry synthesis approach to fabricate nanoporous Cu and copper oxide (CuO) films on silicon substrates and systematically evaluate their UV SERS performance using adenine as a Raman reporter under 325 nm excitation. Among the substrates investigated, nanoporous Cu exhibits the strongest enhancement, enabling adenine detection down to 10 microM. In contrast, no detectable adenine Raman signal is observed under 532 nm excitation, indicating that the enhancement is dominated by a UV induced chemical, charge transfer mechanism rather than conventional electromagnetic enhancement. The Cu substrates further enable the UV Raman spectroscopy of streptavidin, as a test protein, and, more interestingly, the discrimination between L and D tryptophane based solely on differences in UV SERS intensity, without chiral selectors or additional surface functionalization. By varying the substrate rotation speed during metal evaporation, the enantioselective response can be tuned, yielding L over D intensity ratios from 1.10 to 2.35 and demonstrating the critical role of substrate morphology in chiral discrimination. The dry synthesized nanoporous films provide a simpler, scalable, and ligand free fabrication strategy while offering additional capability for enantioselective detection. These findings establish dry processed nanoporous Cu films as promising platforms for UV-SERS biosensing and label free chiral analysis.
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BibTeX
@misc{jin2026nanoporous,
title = {{Nanoporous Copper Films as Platform for UV-SERS: Sensitivity and Ability to Perform Chiral Discrimination}},
author = {Huaizhou Jin and Anastasiia Sapunova and Yanqiu Zou and Ali Douaki and German Lanzavecchia and Nicolo Maccaferri and Costantino De Angelis and Roman Krahne and Zhenrong Zheng and Shangzhong Jin and Denis Garoli},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.02061},
eprint = {2609.02061},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.02061},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Nanoporous Copper Films as Platform for UV-SERS: Sensitivity and Ability to Perform Chiral Discrimination
AU - Huaizhou Jin
AU - Anastasiia Sapunova
AU - Yanqiu Zou
AU - Ali Douaki
AU - German Lanzavecchia
AU - Nicolo Maccaferri
AU - Costantino De Angelis
AU - Roman Krahne
AU - Zhenrong Zheng
AU - Shangzhong Jin
AU - Denis Garoli
PY - 2026
DA - 2026/09/02
PB - arXiv
DO - 10.48550/arxiv.2609.02061
UR - https://arxiv.org/abs/2609.02061
AB - Surface enhanced Raman spectroscopy (SERS) in the ultraviolet (UV) region offers important advantages for biomolecular detection, including resonance enhancement and reduced fluorescence interference. However, the development of UV SERS substrates that combine low cost, reproducibility, and chemical stability remains challenging. Here, we employ a dry synthesis approach to fabricate nanoporous Cu and copper oxide (CuO) films on silicon substrates and systematically evaluate their UV SERS performance using adenine as a Raman reporter under 325 nm excitation. Among the substrates investigated, nanoporous Cu exhibits the strongest enhancement, enabling adenine detection down to 10 microM. In contrast, no detectable adenine Raman signal is observed under 532 nm excitation, indicating that the enhancement is dominated by a UV induced chemical, charge transfer mechanism rather than conventional electromagnetic enhancement. The Cu substrates further enable the UV Raman spectroscopy of streptavidin, as a test protein, and, more interestingly, the discrimination between L and D tryptophane based solely on differences in UV SERS intensity, without chiral selectors or additional surface functionalization. By varying the substrate rotation speed during metal evaporation, the enantioselective response can be tuned, yielding L over D intensity ratios from 1.10 to 2.35 and demonstrating the critical role of substrate morphology in chiral discrimination. The dry synthesized nanoporous films provide a simpler, scalable, and ligand free fabrication strategy while offering additional capability for enantioselective detection. These findings establish dry processed nanoporous Cu films as promising platforms for UV-SERS biosensing and label free chiral analysis.
ER -