Department of Electrical Engineering, Stanford University, Stanford, CA, 94305, USA.
Department of Radiology, Stanford University, Stanford, CA, 94305, USA; Molecular Imaging Program at Stanford, Stanford University, Stanford, CA, 94305, USA.
Biosens Bioelectron. 2021 May 15;180:112823. doi: 10.1016/j.bios.2020.112823. Epub 2020 Nov 26.
Measurement of total protein in urine is key to monitoring kidney health in diabetes. However, most total protein assays are performed using large, expensive laboratory chemistry analyzers that are not amenable to point-of-care analysis or home monitoring and cannot provide real-time readouts. We developed a miniaturized optoelectronic biosensor using a vertical cavity surface-emitting laser (VCSEL), coupled with a fast protein assay based on protein-induced fluorescence enhancement (PIFE), that can dynamically measure protein concentrations in protein-spiked buffer, serum, and urine in seconds with excellent sensitivity (urine LOD = 0.023 g/L, LOQ = 0.075 g/L) and over a broad range of physiologically relevant concentrations. Comparison with gold standard clinical assays and standard fluorimetry tools showed that the sensor can accurately and reliably quantitate total protein in clinical urine samples from patients with diabetes. Our VCSEL biosensor is amenable to integration with miniaturized electronics, which could afford a portable, low-cost, easy-to-use device for sensitive, accurate, and real-time total protein measurements from small biofluid volumes.
检测尿液中的总蛋白含量是监测糖尿病患者肾脏健康的关键。然而，大多数总蛋白检测是使用大型、昂贵的实验室化学分析仪进行的，这些分析仪不适用于即时检测或家庭监测，也无法提供实时读数。我们使用垂直腔面发射激光器 (VCSEL) 开发了一种小型化光电生物传感器，结合基于蛋白诱导荧光增强 (PIFE) 的快速蛋白检测方法，可以在几秒钟内动态测量蛋白缓冲液、血清和尿液中的蛋白浓度，具有出色的灵敏度（尿液检测下限=0.023g/L，检测上限=0.075g/L），且可检测的蛋白浓度范围很广。与金标准临床检测方法和标准荧光检测工具的比较表明，该传感器可以准确可靠地定量检测糖尿病患者的临床尿液样本中的总蛋白。我们的 VCSEL 生物传感器易于与小型化电子设备集成，这可能会提供一种便携式、低成本、易于使用的设备，用于从小体积生物流体中进行敏感、准确和实时的总蛋白测量。
