应用光电二极管阵列的SPR生物传感器微弱信号检测

Detection of Weak Signals Generated by Surface Plasmon Resonance Biomedical Sensors Using Photodiode-Array Device

该文以提升表面等离子共振生物医学传感器的检测能力为目标,用高性能光电二极管阵列为光电转换器件,论证并实现一种可高效抑制噪声的检测方法,利用光电二极管阵列器件可输出参考噪声信号的特性,通过相干消噪结合小波软阈值消噪,使SPR传感器输出信噪比从40dB左右提高到52dB以上.用SPR传感器检测人体免疫球蛋白(IgG)分子特异性结合的实验表明,该方法显著提高了SPR传感器的分辨率,使之可精确检测样液中IgG含量10^(-3)mg/mL量级的微弱变化,精度和分辨率提升一个数量级以上.

This paper proposes an efficient de-noising method using a photodiode-array device to improve detection capability of surface plasmon resonance （SPR） sensors. Using reference noise signals output from the photodiode-array, we combine the coherence de-noising technique and the wavelet de-noising using soft threshold so as to raise the output SNR from 40 dB to over 52 dB. Experiments of human immunoglobulin G （IgG） molecules specific combinations show that the proposed de-noising method can remarkably enhance resolution of SPR sensors. Using this method, the SPR sensor can quantitatively detect tiny change of IgG molecule contents in solution samples with an order of 10-3 mg/mL, showing an improvement of more than one order of magnitude in detection accuracy and resolution.