Developing Integrated Optofluidic Platforms for Cellular Phenotyping.

Abstract

This research demonstrates two optofluidic platforms to address three major problems of current fluorescence-based optical detection methods for cellular phenotyping: (1) limited number of fluorescent probes, (2) laborious and time-consuming assay preparation and manipulation steps, and (3) compromised sensing performance in a point-of-care setting. The first optofluidic platform is called the “microfluidic multispectral flow cytometry (MMFC) device”. The function of the MMFC device is to discriminate multiple cell types based on their fluorescent proteins or surface biomarkers at single cell level with a simplified optical setup. It represents a unique class of optofluidic system incorporating a MEMS-based tunable nanoimprinted grating microdevice, a single excitation laser, and a single PMT detector. The system enables us to achieve in-situ continuous spectral profile detection for bioparticles flowing in a microfluidic channel with high specificity and high speed. The second optofluidic platform is called the “microfluidic immunophenotyping assay (MIPA) device”. The function of the MIPA device is to achieve on-chip cell trapping, cell stimulation and in-situ secreted cytokine detection in one single chip with a shorten assay time and less sample requirements. Compared to previous studies using heterogeneous immunoassay techniques and requiring a longer assay time due to multiple surface immobilization processes and washing steps, our immunophenotyping assay with the MIPA device holds significant promise to open ways for rapid immune status determination in real clinical settings.