Dual-Modulation of Charge Transfer in Surface-Enhanced Raman Scattering for Qualitative and Quantitative Exosome Detection.

@Au nanoprobes, under near-infrared excitation, produce an anti-Stokes emission that overlaps with the vibronic bands of the tagged 4-mercaptopyridine (4-Mpy). Benefiting from this cooperative piezoelectric-photonic mechanism, our platform achieves ultrasensitive detection as low as 40 particles/mL while enabling highly accurate classification (≥98%) of cancer-derived exosomes. This work paves a promising way for developing regulated SERS platforms with broad potential for diverse bioanalytical applications beyond cancer-derived exosome detection.