Study on the thickness of the electric double layer for the performance of protein preconcentration in the nanofluidic concentrator

• Main Authors: Tsai, Kuo-Sheng, 蔡國陞
• Other Authors: 任春平
• Format: Others
• Language: zh-TW
• Published: 2019
• Online Access: http://ndltd.ncl.edu.tw/handle/82b5ja

碩士 === 國立中正大學 === 機械工程系研究所 === 107 === Sample preconcentration is an important step that increases the accuracy of subsequent detection, especially for samples with extremely low concentrations. Due to the overlap of electrical double layers in a nanofluidic channel, the concentration polarization effect can be generated by applying an electric field. A nonlinear electrokinetic flow is induced, which results in the fast accumulation of proteins in front of the induced ionic depletion zone, the so-called exclusion-enrichment effect. The preconcentration chip for proteins was fabricated using simple standard soft lithography with a polydimethylsiloxane (PDMS) replica. A nanofluidic preconcentrator fabricated with the help of junction gap was integrated with Self-as sembled gold nanoparticles (AuNPs). In this way, a protein sample can be driven by electroosmotic flow and accumulated at a specific location In the present study, different Phosphate buffer concentration( 0.1 mM、1 mM、5 mM、10mM、100mM) had different electric double layer thickness, According the experimental results, 5 mM concentration was suitable concentration.