Department of Information Engineering, Electronics and Telecommunications, University of Rome "La Sapienza", Via Eudossiana 18, 00184 Rome, Italy.
Sensors (Basel). 2021 Jan 8;21(2):415. doi: 10.3390/s21020415.
An optoelectronic, integrated system-on-glass for on-chip detection of biomolecules is here presented. The system's working principle is based on the interaction, detected by a hydrogenated amorphous silicon photosensor, between a monochromatic light travelling in a SU-8 polymer optical waveguide and the biological solution under analysis. Optical simulations of the waveguide coupling to the thin-film photodiode with a specific design were carried out. A prototype was fabricated and characterized showing waveguide optical losses of about 0.6 dB/cm, a photodiode shot noise current of about 2.5 fA/Hz and responsivity of 495 mA/W at 532 nm. An electro-optical coupling test was performed on the fabricated device to validate the system. As proof of concept, hemoglobin was studied as analyte for a demonstration scenario, involving optical simulations interpolated with experimental data. The calculated detection limit of the proposed system for hemoglobin concentration in aqueous solution is around 100 ppm, in line with colorimetric methods currently on the market. These results show the effectiveness of the proposed system in biological detection applications and encourage further developments in implementing these kinds of devices in the biomedical field.
这里介绍了一种用于生物分子片上检测的光电集成玻璃上系统。该系统的工作原理基于单色光在 SU-8 聚合物光波导中传播与被分析生物溶液之间的相互作用，该相互作用由氢化非晶硅光电传感器检测。对具有特定设计的薄膜光电二极管与波导耦合进行了光学模拟。制作了一个原型并进行了表征，结果显示波导的光损耗约为 0.6 dB/cm，光电二极管的散粒噪声电流约为 2.5 fA/Hz，在 532nm 时的响应率为 495 mA/W。对所制作的器件进行了光电耦合测试，以验证系统的性能。作为概念验证，以血红蛋白作为分析物进行了演示场景的研究，涉及到光学模拟与实验数据的插值。所提出系统对水溶液中血红蛋白浓度的检测极限约为 100ppm，与市场上现有的比色法相当。这些结果表明了所提出的系统在生物检测应用中的有效性，并鼓励在生物医学领域进一步开发这种类型的器件。
