Department of Electrical Engineering, Indian Institute of Technology Hyderabad, Hyderabad, Telangana, 502285, India.
Mikrochim Acta. 2023 Jul 25;190(8):320. doi: 10.1007/s00604-023-05865-1.
Age-related macular degeneration (AMD) is a progressive chronic neurodegenerative retinal disease leading to vision loss, irreversible blindness, and visual impairment in older adults worldwide. Complement component 3 (C3) protein has been identified as the most predominant biomarker towards early diagnosis of AMD; therefore, there is an utmost requirement for non-invasive detection of C3 protein in the tear fluids of AMD patients. Considering this, we report an insightful electrochemical sensor capable of detecting clinically relevant concentrations ranging from 10 fg/mL to 1 μg/mL using electrospun indium-doped zinc oxide (InZnO) nanofibers as the transducing layer. The InZnO nanofibers have facilitated high anti-C3 antibody loading of 3.42 × 10 mol/cm and enhanced the overall charge transport mechanism at the sensor interface. The biofunctionalization process of the biosensor was investigated thoroughly using X-ray photoelectron spectroscopy (XPS) as well as different electrochemical techniques. The target C3 proteins were captured on the fabricated biosensor surface and determined through changes in charge transfer resistance (R) while executing electrochemical impedance spectroscopy (EIS) and peak current (I) in the case of cyclic voltammetry (CV) and differential pulse voltammetry (DPV), respectively. The InZnO nanofiber-based nano-biosensor demonstrated a very low limit of detections (LODs) of 5.214 fg/mL and 0.241 fg/mL with an excellent sensitivity of 4.6709 (ΔR/R) (g/mL) cm and 54.4939 (ΔI/I)% (g/mL) cm for EIS and DPV techniques, respectively. By virtue of high antibody loading, ultrasensitive and ultra-selective capability, the indium-doped ZnO nanofibers show huge potential to be used as a high-performance diagnostic platform for AMD diagnosis.
年龄相关性黄斑变性（AMD）是一种进行性慢性神经退行性视网膜疾病，导致全球老年人视力下降、不可逆转的失明和视力障碍。补体成分 3（C3）蛋白已被确定为 AMD 早期诊断的最主要生物标志物；因此，非常需要在 AMD 患者的泪液中进行 C3 蛋白的非侵入性检测。考虑到这一点，我们报告了一种有洞察力的电化学传感器，该传感器能够使用电纺铟掺杂氧化锌（InZnO）纳米纤维作为传感层来检测临床相关浓度范围为 10 fg/mL 至 1 μg/mL 的 C3 蛋白。InZnO 纳米纤维促进了 3.42 × 10 mol/cm 的高抗-C3 抗体负载，并增强了传感器界面的整体电荷传输机制。使用 X 射线光电子能谱（XPS）以及各种电化学技术彻底研究了生物传感器的生物功能化过程。目标 C3 蛋白被捕获在制备的生物传感器表面上，并通过在执行电化学阻抗谱（EIS）时电荷转移电阻（R）的变化以及在循环伏安法（CV）和差分脉冲伏安法（DPV）的情况下峰电流（I）来确定。基于 InZnO 纳米纤维的纳米生物传感器表现出非常低的检测限（LOD）为 5.214 fg/mL 和 0.241 fg/mL，具有出色的灵敏度 4.6709（ΔR/R）（g/mL）cm 和 54.4939（ΔI/I）%（g/mL）cm，分别用于 EIS 和 DPV 技术。由于具有高抗体负载、超灵敏和超高选择性，掺铟氧化锌纳米纤维具有成为 AMD 诊断的高性能诊断平台的巨大潜力。
