Label-free navigation system for grading prostate tumour malignancy in situ via tissue pH and prostate-specific antigen activity.

Radical prostatectomy is a standard curative approach for high-risk prostate cancer, yet accurately defining tumour margins during surgery remains a major challenge. Intraoperative assessment of prostate tumour malignancy-particularly those with high aggressiveness catalogued in Gleason grade group (GG) ≥ 3-is crucial to prevent positive surgical margins and minimize postoperative complications. Here we develop a surface-enhanced Raman scattering (SERS)-based navigation system for intraoperative localization of high-grade malignant regions by simultaneously accessing tissue acidity and prostate-specific antigen (PSA) enzymatic activity. This system integrates a sampling pen for automated biomarker extraction from tissue surfaces, a nano-imprinted SERS array producing a ratiometric Raman signal in response to acidity and PSA activity, and a two-dimensional deep-learning model for rapid Raman spectral interpretation. We show that the system can intraoperatively identify GG ≥ 3 malignancies in fresh prostate tissues from 144 Chinese patients with an area under the receiver operating characteristic curve of 0.89. This SERS-based navigation system holds strong potential to enhance surgical precision, minimize tumour residue and ultimately improve patient outcomes.