Department of Chemistry and Institute of BioPhysio-Sensor Technology , Pusan National University , Busan 46241 , South Korea.
Korea Mouse Metabolic Phenotyping Center, Lee Gil Ya Cancer and Diabetes Institute, and Internal Medicine, Gil Medical Center , Gachon University , Incheon 21565 , Republic of Korea.
Anal Chem. 2019 Nov 5;91(21):14109-14116. doi: 10.1021/acs.analchem.9b03953. Epub 2019 Oct 10.
In this study, we have established the separation of Au nanoparticles (AuNPs) using a symmetrical AC electric field applied-electrochemical microfluidic device composed of carbon channel and detection electrodes. The lateral movement of AuNPs in the channel under the AC field was analyzed by simulation using the mathematically derived equations, which were formulated from Newtonian fluid mechanics. It shows that the nanoparticles are precisely separated according to their respective mass or size difference in a short time. The experimental parameters affecting the separation and detection of AuNPs were optimized in terms of applied frequency, amplitude, flow rate, buffer concentration, pH dependency, and temperature. The final separation was performed at 1.0 V amplitude with 8.0 MHz frequency at 0.4 μL/min flow rate for the separation, and the potential of 1.0 V was applied for the amperometric detection of AuNPs in a 0.1 M PBS. Before and after the separation, AuNPs (diameter range: 3-60 nm) were confirmed by UV-visible spectroscopy and transmission electron microscopy. In this case, the separation resolution was 3 nm with an enhanced separation efficiency of up to 597,503 plates/m for the AuNPs. In addition, the amperometric current response of the detection electrode under the AC field application was also enhanced by the sensitivity 5-fold compared with the absence of the AC field.
在这项研究中，我们使用由碳通道和检测电极组成的对称交流电场应用电化学微流控装置来分离金纳米粒子（AuNPs）。通过使用从牛顿流体力学推导出的数学方程对 AuNPs 在交流场下的横向运动进行模拟分析，表明可以在短时间内根据各自的质量或尺寸差异精确分离纳米粒子。根据施加频率、幅度、流速、缓冲液浓度、pH 值依赖性和温度优化了影响 AuNPs 分离和检测的实验参数。最终分离在 0.4 μL/min 的流速下以 1.0 V 的幅度和 8.0 MHz 的频率进行，在 0.1 M PBS 中对 AuNPs 进行安培检测时施加 1.0 V 的电势。在分离前后，通过紫外可见光谱和透射电子显微镜证实了 AuNPs（直径范围：3-60nm）的存在。在这种情况下，分离分辨率为 3nm，AuNPs 的分离效率提高了 597503 倍。此外，与没有交流场的情况相比，在交流场应用下检测电极的安培电流响应也提高了 5 倍。
