Frequency Shift Raman-Based Sensing of Serum MicroRNAs for Early Diagnosis and Discrimination of Primary Liver Cancers.

Frequency shift surface-enhanced Raman scattering (SERS) achieves multiplex microRNA sensing for early serological diagnosis of, and discrimination between, primary liver cancers in a patient cohort for whom only biopsy is effective clinically. Raman reporters microprinted on plasmonic substrates shift their vibrational frequencies upon biomarker binding with a dynamic range allowing direct, multiplex assay of serum microRNAs and the current best protein biomarker, α-fetoprotein. Benchmarking against current gold-standard polymerase chain reaction and chemiluminescence methods validates the assay. The work further establishes the frequency shift approach, sensing shifts in an intense SERS band, as a viable alternative to conventional SERS sensing which involves the more difficult task of resolving a peak above noise at ultralow analyte concentrations.