The AlGaN/GaN-based sensor is a promising POCT (point-of-care-testing) device featuring miniaturization, low cost, and high sensitivity. BNP is an effective protein biomarker for the early diagnosis of HF (heart failure). In this work, a novel AlGaN/GaN device with the Kelvin connection structure and the corresponding detection technique was proposed. This technique can effectively suppress the background noise and improve the SNR (signal-to-noise ratio). A BNP detection experiment was carried out to verify the effectiveness of this technique. It is shown that compared with that of the traditional detection method, the LOD (limit of detection) was improved from 0.47 ng/mL to 1.29 pg/mL. The BNP detection experiment was also carried out with a traditional electrochemical Au-electrode sensor with the same surface functionalization steps. The AlGaN/GaN sensor showed a better LOD than the Au-electrode sensor. Moreover, the influence of AlGaN/GaN sensor package on background noise was investigated with the mechanism of the noise source revealed. Finally, based on the optimized package, the optimal SNR quiescent operating point of the AlGaN/GaN sensor was determined. By biasing the sensor at the optimal quiescent operating point and immobilizing the magnetic beads with anti-BNP on the gate of the AlGaN/GaN sensor, the LOD for BNP detection was further improved to 0.097 pg/mL.

基于 AlGaN/GaN 的传感器是一种很有前途的 POCT（即时检测）设备，具有小型化、低成本和高灵敏度的特点。BNP 是一种有效的蛋白质生物标志物，可用于早期诊断 HF（心力衰竭）。在这项工作中，提出了一种具有开尔文连接结构的新型 AlGaN/GaN 器件和相应的检测技术。该技术可以有效抑制背景噪声，提高SNR（信噪比）。进行了 BNP 检测实验以验证该技术的有效性。结果表明，与传统检测方法相比，LOD（检测限）从0.47 ng/mL提高到1.29 pg/mL。BNP 检测实验也使用具有相同表面功能化步骤的传统电化学 Au 电极传感器进行。AlGaN/GaN 传感器显示出比 Au 电极传感器更好的 LOD。此外，研究了 AlGaN/GaN 传感器封装对背景噪声的影响，揭示了噪声源的机制。最后，基于优化的封装，确定了 AlGaN/GaN 传感器的最佳 SNR 静态工作点。通过在最佳静态工作点偏置传感器并在 AlGaN/GaN 传感器的栅极上固定带有抗 BNP 的磁珠，BNP 检测的 LOD 进一步提高到 0.097 pg/mL。确定了 AlGaN/GaN 传感器的最佳 SNR 静态工作点。通过在最佳静态工作点偏置传感器并在 AlGaN/GaN 传感器的栅极上固定带有抗 BNP 的磁珠，BNP 检测的 LOD 进一步提高到 0.097 pg/mL。确定了 AlGaN/GaN 传感器的最佳 SNR 静态工作点。通过在最佳静态工作点偏置传感器并在 AlGaN/GaN 传感器的栅极上固定带有抗 BNP 的磁珠，BNP 检测的 LOD 进一步提高到 0.097 pg/mL。