Temperature gap drives directed diffusion in microfluidic chip system

Diffusion plays a critical role in establishing functional bio/solid soft interfaces for bioassays, biosensors, and biofuel cells. An understanding of micro-diffusion near the interface is significant for developing high-performance bioassays, biosensors, and biofuel cells. Herein, we explored micro-diffusion behavior at different temperature gaps in microfluidic chip and enzyme-linked immunosorbent assay (ELISA) microplates. It exhibited that temperature gap could distinctly promote directional diffusion of molecules in microfluidic chip from high concentration zone to low concentration zone. In addition, experimental results of specially designed ELISA also partly confirmed that the temperature gap could effectively improve the performance of ELISA by 54.5%. In compared with conventional ELISA, the as-prepared temperature-gap functional module in microfluidic chip has obvious advantages of miniaturization, integration, customization, and low cost. All in all, the current work indicates that temperature-gap function has great potential in biomedical detection, food safety, and so on. It can be utilized to develop novel biological detection approaches and related instruments or microfluidic chips.