Yoo Jason J, Anderson Morgan J, Alligrant Timothy M, Crooks Richard M
Department of Chemistry, Center for Electrochemistry, and the Center for Nano- and Molecular Science and Technology, The University of Texas at Austin , 105 East 24th Street Stop A5300, Austin, Texas 78712-1224, United States.
Anal Chem. 2014 May 6;86(9):4302-7. doi: 10.1021/ac404093c. Epub 2014 Apr 18.
We report electrochemical detection of collisions between individual magnetic microbeads, present at subattomolar concentrations, and electrode surfaces. This limit of detection is 4 orders of magnitude lower than has been reported previously, and it is enabled by using a magnetic field to preconcentrate the microbeads prior to detection in a microfluidic electrochemical cell. Importantly, the frequency of collisions between the microbeads and the electrode is not compromised by the low concentration of microbeads. These findings represent an unusual case of detecting individual electrochemical events at very low analyte concentration. In addition to experiments supporting these claims, finite-element simulations provide additional insights into the nature of the interactions between flowing microbeads and their influence on electrochemical processes.
我们报告了对亚阿托摩尔浓度下单个磁性微珠与电极表面之间碰撞的电化学检测。此检测限比之前报道的低4个数量级，这是通过在微流控电化学池中检测前利用磁场对微珠进行预浓缩实现的。重要的是，微珠与电极之间的碰撞频率不会因微珠的低浓度而受到影响。这些发现代表了在极低分析物浓度下检测单个电化学事件的一个特殊案例。除了支持这些说法的实验外，有限元模拟还提供了关于流动微珠之间相互作用的性质及其对电化学过程影响的更多见解。
