Surface-enhanced Raman spectroscopy for comprehensive urinalysis: advances, challenges, and clinical perspectives.

Urine is an information-rich, noninvasive biofluid that reflects systemic and urological physiology through endogenous metabolites, disease-associated biomarkers, and residues of therapeutic drugs. Surface-enhanced Raman spectroscopy (SERS) has emerged as a powerful, label-free platform for urinary molecular profiling, offering rapid readouts with high sensitivity and minimal sample preparation. This review critically examines recent advances in SERS-enabled urinalysis for urological and related clinical applications, including assessment of renal function, detection of urinary tract infection pathogens and antimicrobial resistance signatures, therapeutic drug monitoring, and cancer screening based on metabolic and biomarker patterns. We highlight how developments in nanostructured substrates, microfluidic sample handling, and data-driven spectral interpretation (chemometrics and machine learning) are enabling multiplexed detection and improving the linkage between spectral features and clinically actionable endpoints. Although further improvements are needed in detection reproducibility and the establishment of standardized spectral databases, SERS-based urinalysis shows significant potential for advancing precise diagnosis and treatment of urological diseases.