Bhattacharjee Mitradip, Middya Sagnik, Escobedo Pablo, Chaudhuri Joydip, Bandyopadhyay Dipankar, Dahiya Ravinder
Bendable Electronics and Sensing Technologies (BEST) group, University of Glasgow - G12 8QQ, Glasgow, United Kingdom; Electrical Engineering and Computer Science, Indian Institute of Science Education and Research (IISER) Bhopal, 462066, MP, India.
Centre for Nanotechnology, Indian Institute of Technology Guwahati, 781039, Assam, India.
Biosens Bioelectron. 2020 Oct 1;165:112333. doi: 10.1016/j.bios.2020.112333. Epub 2020 Jun 11.
Concentration of α-amylase in human serum is a key indicator of various pancreatic ailments and an affordable point-of-care detection of this biomarker can benefit millions suffering from these diseases. In view of this situation, we report the development of a flexible patch-sensor, which simply requires a microdroplet of aqueous starch-FeSO solution to detect α-amylase in serum. The detection is achieved through the generation of mixing vortices (12 rpm) inside the droplet with the help of an imposed thermal gradient. Such vortices due to Marangoni and natural convections are found to be strongest at an optimal temperature difference of ~18 °C - 23 °C across the droplet which in turn facilitate mixing and promote the specific starch-amylase enzymatic reaction. Subsequently, the large (80%) variation in the electrical resistance across the droplet is correlated to detect the level of the α-amylase in the analyte. Importantly, the sensor can detect even in the limits of 15-110 units/liter. Further, the sensitivity of flexible sensors is ~8.6% higher than the non-flexible one. Interestingly, the sensitivity of the proposed sensor has been nearly three-times than the previously reported optical ones. The results of patch-sensor match very closely with the standard path-lab tests while detecting unknown level of amylase in serum. The prototype has shown significant potential to translate into an affordable device for the real-time detection and easy prognosis of pancreatic disorders.
人血清中α-淀粉酶的浓度是各种胰腺疾病的关键指标，对这种生物标志物进行经济实惠的即时检测可使数百万患有这些疾病的人受益。鉴于这种情况，我们报告了一种柔性贴片传感器的研发情况，该传感器仅需一滴淀粉 - 硫酸亚铁水溶液即可检测血清中的α-淀粉酶。检测是通过在液滴内部借助施加的热梯度产生混合涡旋（约12转/分钟）来实现的。由于马兰戈尼效应和自然对流产生的这种涡旋在液滴上约18°C - 23°C的最佳温差下最强，这反过来又促进了混合并推动了特定的淀粉 - 淀粉酶酶促反应。随后，液滴两端电阻的大幅变化（约80%）与检测分析物中α-淀粉酶的水平相关联。重要的是，该传感器甚至可以在15 - 110单位/升的范围内进行检测。此外，柔性传感器的灵敏度比非柔性传感器高约8.6%。有趣的是，所提出的传感器的灵敏度几乎是先前报道的光学传感器的三倍。在检测血清中未知水平的淀粉酶时，贴片传感器的结果与标准实验室检测结果非常接近。该原型已显示出巨大的潜力，有望转化为一种经济实惠的设备，用于胰腺疾病的实时检测和简易预后。
