Thuy Tran Nguyen Thanh, Tseng Tina T-C
Department of Chemical Engineering, National Taiwan University of Science and Technology, Taipei 10607, Taiwan.
Sensors (Basel). 2016 May 26;16(6):767. doi: 10.3390/s16060767.
In this study, a miniaturized biosensor based on permselective polymer layers (overoxidized polypyrrole (Ppy) and Nafion(®)) modified and enzyme (glutamate oxidase (GlutOx)) immobilized micro-platinum wire electrode for the detection of alanine aminotransferase (ALT) was fabricated. The proposed ALT biosensor was measured electrochemically by constant potential amperometry at +0.7 V vs. Ag/AgCl. The ALT biosensor provides fast response time (5 s) and superior selectivity towards ALT against both negatively and positively charged species (e.g., ascorbic acid (AA) and dopamine (DA), respectively). The detection range of the ALT biosensor is found to be 10-900 U/L which covers the range of normal ALT levels presented in the serum and the detection limit and sensitivity are found to be 8.48 U/L and 0.059 nA/(U/L·mm²) (N = 10), respectively. We also found that one-day storage of the ALT biosensor at -20 °C right after the sensor being fabricated can enhance the sensor sensitivity (1.74 times higher than that of the sensor stored at 4 °C). The ALT biosensor is stable after eight weeks of storage at -20 °C. The sensor was tested in spiked ALT samples (ALT activities: 20, 200, 400, and 900 U/L) and reasonable recoveries (70%107%) were obtained.
在本研究中，制备了一种基于选择性渗透聚合物层（过氧化聚吡咯（Ppy）和Nafion®）修饰且固定有酶（谷氨酸氧化酶（GlutOx））的微型铂丝电极的生物传感器，用于检测丙氨酸转氨酶（ALT）。所提出的ALT生物传感器通过恒电位安培法在相对于Ag/AgCl为+0.7 V的电位下进行电化学测量。该ALT生物传感器响应时间快（约5 s），对ALT具有优异的选择性，对带负电和正电的物质（例如分别为抗坏血酸（AA）和多巴胺（DA））均有良好的选择性。发现ALT生物传感器的检测范围为10 - 900 U/L，涵盖了血清中正常ALT水平的范围，检测限和灵敏度分别为8.48 U/L和0.059 nA/(U/L·mm²)（N = 10）。我们还发现，在制造后立即将ALT生物传感器在-20°C下储存一天可以提高传感器的灵敏度（比在4°C下储存的传感器高1.74倍）。该ALT生物传感器在-20°C下储存八周后仍保持稳定。该传感器在加标ALT样品（ALT活性：20、200、400和900 U/L）中进行了测试，并获得了合理的回收率（70%~107%）。
