Optical trapping-assisted SERS platform for chemical and biosensing applications: Design perspectives

Abstract Useful approaches to tackle Brownian motion of micro/nanoparticles and overcome the poor reproducibility of surface-enhanced Raman scattering (SERS) events are highly desirable, especially for performing SERS sensing in ultra-low concentration of analytes. When integrated with the SERS measurement system, optical trapping is a versatile approach for manipulating particles and thereby improving the SERS performance. A review of the recent research advancements in optical trapping-assisted SERS platform can provide critical inputs for optimizing SERS-based sensing methods for real-life applications. In this paper, we present an in-depth review on the systematic classification of optical trapping-assisted ( e.g. , far-field and near-field optical tweezers) SERS sensing platform and discuss its latest practical applications in biosensing, bioimaging, chemical monitoring, particle manipulation, single cell analysis, etc . Also, we summarize some important strategies to suppress the plasmonic heating effect which hinders the stability of optical tweezers. Furthermore, we also propose non-optical trapping approaches for manipulating nanoparticles/molecules that are promising for prospective SERS sensing. For example, plasmonic heating is not completely deleterious to particle manipulation. Particularly, plasmon-enhanced thermophoresis technique is a useful non-optical approach for trapping particles/molecules and incorporating with SERS detection. Finally, we conclude with future perspectives for designing the new generation of optical tweezers.