Jen Chun-Ping, Amstislavskaya Tamara G, Chen Kuan-Fu, Chen Yu-Hung
Department of Mechanical Engineering and Advanced Institute of Manufacturing with High-Tech Innovations, National Chung Cheng University, Chia Yi, Taiwan, R.O.C.
Laboratory of Experimental Models of Emotional Pathology, Scientific Research Institute of Physiology and Basic Medicine, Novosibirsk, Russia.
PLoS One. 2015 May 13;10(5):e0126641. doi: 10.1371/journal.pone.0126641. eCollection 2015.
The preconcentration of proteins with low concentrations can be used to increase the sensitivity and accuracy of detection. A nonlinear electrokinetic flow is induced in a nanofluidic channel due to the overlap of electrical double layers, resulting in the fast accumulation of proteins, referred to as the exclusion-enrichment effect. The proposed chip for protein preconcentration was fabricated using simple standard soft lithography with a polydimethylsiloxane replica. This study extends our previous paper, in which gold nanoparticles were manually deposited onto the surface of a protein preconcentrator. In the present work, nanofractures were formed by utilizing the self-assembly of gold-nanoparticle-assisted electric breakdown. This reliable method for nanofracture formation, involving self-assembled monolayers of nanoparticles at the junction gap between microchannels, also decreases the required electric breakdown voltage. The experimental results reveal that a high concentration factor of 1.5×10(4) for a protein sample with an extremely low concentration of 1 nM was achieved in 30 min by using the proposed chip, which is faster than our previously proposed chip at the same conditions. Moreover, an immunoassay of bovine serum albumin (BSA) and anti-BSA was carried out to demonstrate the applicability of the proposed chip.
低浓度蛋白质的预浓缩可用于提高检测的灵敏度和准确性。由于双电层的重叠，在纳米流体通道中会诱导产生非线性电动流，导致蛋白质快速积累，这被称为排斥富集效应。所提出的用于蛋白质预浓缩的芯片是使用简单的标准软光刻技术和聚二甲基硅氧烷复制品制造的。本研究扩展了我们之前的论文，在那篇论文中，金纳米颗粒是手动沉积在蛋白质预浓缩器的表面上。在当前工作中，利用金纳米颗粒辅助电击穿的自组装形成了纳米裂缝。这种可靠的纳米裂缝形成方法，涉及在微通道之间的连接间隙处纳米颗粒的自组装单层，也降低了所需的电击穿电压。实验结果表明，使用所提出的芯片，在30分钟内对于浓度极低为1 nM的蛋白质样品实现了1.5×10(4)的高浓缩因子，这比在相同条件下我们之前提出的芯片更快。此外，进行了牛血清白蛋白（BSA）和抗BSA的免疫测定，以证明所提出芯片的适用性。
