PDF(Pubmed)
Abstract：
Japanese encephalitis (JE), a neglected tropical zoonotic disease prevalent in south-east Asian and western pacific countries, caused by the flavivirus JE virus (JEV), has a dearth of electrochemical point-of-care (PoC) diagnostic tools available to manage endemic breakouts. To overcome this, we have developed a screen-printed carbon electrode (SPCE) immunosensor for rapid PoC detection of JEV nonstructural 1 (NS1) antigen (Ag), found circulating in serum of infected individuals using a smartphone based portable \"Sensit\" device. The modification of SPCE surface with JEV NS1 antibody (Ab) was confirmed via observation of globular protein structures via scanning electron microscopy (SEM), increase in electrode surface hydrophilicity via contact angle measurement and decrease in current via differential pulse voltammetry (DPV). The fabrication and testing parameters were optimized based on highest current output obtained using DPV. The SPCE was tested for detection limit of target JEV NS1 Ag ranging from 1 fM to 1 μM, which was determined as 0.45 fM in spiked serum. The disposable immunosensor was also found to be highly specific in detecting JEV NS1 Ag over other flaviviral NS1 Ag. Finally, the modified SPCE was clinically validated by testing 62 clinical JEV samples using both a portable miniaturized electrochemical \"Sensit\" device coupled with a smartphone and a laboratory-based potentiostat. The results were corroborated with gold-standard RT-PCR and showed 96.77% accuracy, 96.15% sensitivity, and 97.22% specificity. Hence, this technique may further be developed into a one-step rapid diagnostic tool for JEV, especially in rural areas.
摘要：
日本脑炎(JE),一种在东南亚和西太平洋国家普遍存在的被忽视的热带人畜共患疾病，由黄病毒JE病毒（JEV）引起，缺乏可用于管理地方性爆发的电化学护理点（PoC）诊断工具。为了克服这一点，我们开发了一种丝网印刷碳电极（SPCE）免疫传感器，用于快速检测JEV非结构1（NS1）抗原（Ag）的PoC，发现使用基于智能手机的便携式“Sensit”设备在感染者的血清中循环。通过扫描电子显微镜（SEM）观察球状蛋白结构，证实了JEVNS1抗体（Ab）对SPCE表面的修饰。通过接触角测量增加电极表面亲水性和通过差分脉冲伏安法(DPV)降低电流。基于使用DPV获得的最高电流输出来优化制造和测试参数。测试了SPCE对目标JEVNS1Ag的检测限，范围为1fM至1μM，在加标血清中测定为0.45fM。还发现一次性免疫传感器在检测JEVNS1Ag方面比其他黄病毒NS1Ag具有高度特异性。最后,通过使用便携式微型化电化学\"Sensit\"装置以及智能手机和基于实验室的恒电位仪测试62份临床JEV样本,对改良的SPCE进行了临床验证.结果经金标准RT-PCR证实,准确率为96.77%,96.15%灵敏度,和97.22%特异性。因此，这种技术可能会进一步发展成为JEV的一步快速诊断工具，尤其是在农村地区。
