Actively tunable piezoelectric SERS platform for ultrasensitive and label-free detection of cytomegalovirus in diverse body fluids.

Cytomegalovirus infection poses a major health threat to neonates and immunocompromised individuals, necessitating rapid and sensitive diagnostic methods. In this work, we exploited an actively tunable surface-enhanced Raman scattering (SERS) platform through the rational design of polyvinylidene fluoride (PVDF) nanofibers decorated with Ti3C2 nanosheets (NSs) for cytomegalovirus detection. This SERS platform exhibited excellent reproducibility and long-term stability, demonstrating its reliable SERS performance. In particular, through the enhanced charge transfer (CT) induced by strain-induced charge polarization, the substrate achieved an ultra-high enhancement factor as 2.68 × 107 under an optimized pressure of 20 N. More importantly, this active tunability enabled the substrate to regulate SERS activity through controlled pressure modulation, thereby ensuring robust detection of cytomegalovirus in diverse biological fluids, including aqueous humor, serum, and urine. Furthermore, the recovery rates of cytomegalovirus signals in all tested biological fluids were progressively improved as the applied mechanical pressure increased, demonstrating that the piezoelectric modulation can actively enhance signal amplification in different complex matrices. This work establishes a high-performance piezoelectric-enhanced SERS platform capable of overcoming complex biofluid backgrounds for reliable viral detection, which demonstrates significant potential for early clinical diagnosis of cytomegalovirus infections.