Enhancing Raman Scattering Via Synergistical Strategies

Surface-enhanced Raman scattering(SERS),a rapid nondestructive molecular analysis technique featuring high sensitivity and selectivity,has been extensively applied in the fields of material science,environmental analysis,biomedicine,etc.At present,revealing enhancement mechanisms,discovering new SERS materials,preparing high-performance substrates,developing new detection technologies and practical applications,are all hot research topics in the field of SERS.Some evidences show that synergistical strategies are effective in promoting SERS performance in the aspects of detection limit,signal uniformity,signal reproducibility,stability and biocompatibility.Therefore,we propose several synergistical strategies in promoting SERS performance in noble-metal-based and semiconductor-based systems.Our studies are outlined as followings:1.We proposed a synergistical strategy in promoting SERS performance based on a hierarchically structured micromotor(HSM)system.We adopted nanoimprint and rolling origami techniques to assembly high-density plasmonic hotspots on the outer wall of HSM.This design combines active molecular enrichment of micromotor with high SERS activity of its outer wall,synergistically realizing ultrasensitive SERS sensing.Active enrichment manner is revealed to be effective in accelerating the process of molecular adsorption and collecting more molecules adjacent to the hotspots.2.We proposed a synergistical strategy in promoting SERS performance by integrating amorphous and nonstoichiometric features in WO₃ semiconducting system.This integration enables synergistically enhanced photoinduced charge transfer resonance between analytes and substrate,consequently accomplishing high SERS activity.3.We proposed a synergistical strategy based on a Zn O_1-x whispering-gallery mode(WGM)cavity featuring nonstoichiometric semiconducting property.This combination enables that the high SERS intensity produced by its non-stoichiometric feature are further enhanced through WGM cavity-induced Purcell effect.Its nonstoichiometric feature and unique geometrical structure could lead to a synergy to realize ultrasensitive SERS sensing.