Plasmon waveguide resonance for tag-free selective Raman detection of biochemical composition in single-cell

Highly selective and non-radioactive Raman detection of the biochemical composition of living single-cell is a key method of evaluating complex biological reaction processes. Conventional selective Raman detection relies on tagging technology to separate the Raman signals from the different cell structures, which involves both a complex synthesis process and a long incubation time. To address this, we present a tag-free Raman selective detection with plasmon waveguide resonance (PWR). PWR biochemical composition detection exhibits a high longitudinal spatial resolution based on the surface and bulk response of low- and high-order modes. Hence, compared with conventional selective Raman detection with tagging technology, it can distinguish Raman signals from cell structures more effectively, without an antibody and label, providing effective tag-free selective detection with high spatial resolution. In addition, rapid selective detection can be achieved using the PWR Raman scattering biochemical composition detection, thereby improving the stability of a living single cell without a long incubation time. Moreover, the electromagnetic field of the evanescent field can be significantly amplified by the proposed PWR biochemical composition detection, which also enhances the Raman signal with high sensitivity without requiring a complicated fabrication process. The proposed PWR has potential applications in drug release and living-cell analysis.