Label-Free Detection of Immunoglobulin G Based On Silicon-on-Insulator Microring Resonator Analysis System Integrated with Microfluidic Channels / 分析化学

ABSTRACT

The microfluidic channels integrated with microring resonator were designed. The salt coalescence on chip surface caused by liquid volatilization in open environment was avoided and only 30 μL of reaction solution was consumed. These channels significantly reduced the experiment cost. The design, fabrication and characterization of a highly sensitive and label-free silicon-on-insulator (SOI) microring optical resonator integrated with the microfluidic channels were demonstrated. The radius of the microring was 5 μm and the straight waveguide with a width of 450 nm was employed in the microring resonator. The microring resonator device had many advantages such as high sensitivity, label-free and real-time detection. Using different concentrations of ethanol solution with known refractive indices, the refractive index detection sensitivity was 76.09 nm/RIU and the volume refractive index detection limit was 5.25×10Symbolm_4 RIU. We also demonstrated the label-free quantitative specific detections of human immunoglobulin G (IgG) solutions using an antibody-modified microring resonator by measuring the resonance wavelength shift resulting from refraction index changes causing by the immobilization of antibodies and specific recognition between antibodies and antigens, respectively. The results showed that the microring optical resonator could real-time monitor the reaction between biological molecules, the resonator could be used in the quantitative detection and biological sensing.