GaN photonic microchip for label-free monitoring of single-cell calcium dynamics

Abstract

Calcium signaling dynamics at the single-cell level are crucial to cellular processes such as immune response and cancer development. Herein, we designed and fabricated a gallium -nitride (GaN)-based photonic microchip for label-free monitoring of calcium dynamics in individual cells. The platform can capture the refractive index variations of cells induced by calcium signaling. The sensing throughput of the system is scalable by aligning working units into arrays. As a result, it allows for precise and continuous monitoring of calcium signals in individual cells and permits visualizing cellular heterogeneity via concurrent observation of multiple cells. A complete working prototype system was created using a portable electronic system and a smartphone app.