Tip-assisted Raman Thermal Probing and Nanoscale Trapping

Precise control and measurement of nanoparticles using low-power optical tweezers are pivotal for advancing single-particle analysis, nanoscale sensing, and energy transport research. In this work, we present the tip-assisted nanoparticle capture system that simultaneously achieves localized temperature probing and nanoparticle trapping, significantly lowering the required laser power input. Unlike traditional metal-tip plasmonic techniques that predominantly rely on intense electric field gradients, our approach employs a silicon nanotip under resonant laser excitation, uniquely integrating optical forces, thermophoretic forces, and interatomic interactions for stable nanoparticle confinement. This synergistic collaboration mechanism enables approximately a 42% reduction in laser power density compared to conventional bowtie nanoaperture methods. This experimental method achieved direct and simultaneous Raman-based measurements of localized thermal dynamics, providing new insights into nanoscale thermodynamics during optical trapping. Additionally, the silicon nanotip demonstrates reduced thermal transport due to its confined nanoscale geometry, aligning closely with our theoretical predictions. Our integrated strategy of efficient nanoparticle manipulation coupled with precise thermal probing not only enhances overall energy efficiency but also broadens the scope of potential applications in cutting-edge nanoscience and nanotechnology.