In situ intracellular Raman spectroscopic detection with graphene-based thermoelectric optical tweezers

Label-free Raman spectroscopic detection of cellular elements is an important technique for biological science applications; however, the implementation of proactive intracellular detection remains a challenge. In this work, we demonstrate a graphene-based thermoelectric optical tweezers system for in situ intracellular Raman spectral detection on-a-chip applications. Because of the excellent photothermal conversion effect of the graphene substrate, a potent thermoelectric effect is generated to not only strengthen the trap for biological cells, but also accelerate metallic nanoparticles to permeate into these cells for intracellular Raman enhancement. An in situ intracellular Raman spectrum is thus acquired that offers the opportunity to distinguish the intracellular elements. This work provides a promising approach for use in cytobiology research and is expected to enable exciting new applications in the detection of complex intracellular life processes.