Label-free three-dimensional cellular detection and analysis using holographic tomography and Raman tweezers spectroscopy

This paper presents an innovative multimodal detection system that integrates holographic tomography with Raman tweezers spectroscopy for label-free cellular detection, providing three-dimensional (3D) cell morphology and biochemical composition analysis. Holographic tomography (HT) provides detailed 3D cell morphological images and spatial coordinates, while Raman tweezers spectroscopy (RTS) is employed to analyze biochemical characteristics within specific region of interest (ROI) based on a novel coordinate linking technique for effective connection between HT space and RTS space. The system achieves precise probing and detection with a positioning accuracy of 120 nm and an axial accuracy of 400 nm. Experimental results demonstrate its effectiveness in detecting and analyzing the 3D internal structures and the biochemical compositions of the human retinal pigment epithelial (ARPE-19) cells.