A reusable and batch-produced SERS platform for label-free detection of kidney stones in urine

• Published in: Microchemical journal Vol. 217; p. 115047
• Main Authors: Qiu, Xinhao, Wu, Junzheng, Gao, Xingen, Zhong, Zhenzhe, Feng, Chao, Qiao, Wei, Yi, Cong, Zhang, Hongyi, Lin, Juqiang
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.10.2025
• Subjects: Kidney stones; Silver deposited on scratched aluminum; Support vector machine; Surface-enhanced Raman spectroscopy; Silver deposited on scratched aluminum; Support vector machine; Surface-enhanced Raman spectroscopy; Kidney stones
• ISSN: 0026-265X
• DOI: 10.1016/j.microc.2025.115047

In recent years, reusable, scalable, and conveniently fabricated label-free surface-enhanced Raman spectroscopy (SERS) substrates developed via rapid and practical green synthesis routes have attracted widespread attention in biofluid analysis and clinical diagnostics. In this study, we designed and fabricated a cost-effective, convenient, reusable, and scalable SERS detection platform specifically tailored for rapid and accurate discrimination of kidney stone-related urine samples. The platform is fabricated from silver deposited on scratched aluminum, referred to as SDSA, prepared by mechanically regulating the micro/nanostructures on commercial aluminum foil followed by uniform silver film deposition. This approach avoids complex nanomaterial synthesis and enables facile, environmentally friendly large-scale production. The SDSA substrate demonstrates excellent reusability and long-term stability, with high sensitivity (detection limit down to 10−7 M) and robust signal reproducibility (RSD = 7.08 %) toward the standard probe molecule Rhodamine 6G (R6G). By combining principal component analysis (PCA) with support vector machine (SVM) algorithms, the platform achieves classification accuracies exceeding 92 % across multiple groups, with a peak area under the curve (AUC) of 0.99, significantly enhancing automated recognition and diagnostic performance. These results highlight the broad potential of the SDSA substrate as a green, economical, convenient, reusable, and scalable solution for label-free urine SERS analysis and non-invasive diagnosis of urinary system diseases. A rapidly synthesized, green scratch-induced silver-coated aluminum (SDSA) SERS substrate with simple fabrication and low cost was developed. The substrate demonstrates excellent signal enhancement and reusability. Combined with PCA-SVM analysis, it enables rapid label-free detection of kidney stone urine samples, showing promising clinical potential. [Display omitted] •Green, rapid, low-cost fabrication of scratch-induced SDSA SERS substrates.•Reusable, stable SDSA enables repeated urine SERS analyses.•SDSA + PCA-SVM classifies kidney stone urine with > 92 % accuracy.•(4)Batch-produced SDSA supports convenient, label-free, non-invasive diagnostics.