MESA+ Institute for Nanotechnology , University of Twente , PO Box 217, 7500 AE Enschede , The Netherlands.
Anal Chem. 2018 Jun 19;90(12):7127-7130. doi: 10.1021/acs.analchem.8b01719. Epub 2018 May 29.
Nanoscale channels and electrodes for electrochemical measurements exhibit extreme surface-to-volume ratios and a correspondingly high sensitivity to even weak degrees of surface interactions. Here, we exploit the potential-dependent reversible adsorption of outer-sphere redox species to modulate in space and time their concentration in a nanochannel under advective flow conditions. Induced concentration variations propagate downstream at a species-dependent velocity. This allows one to amperometrically distinguish between attomole amounts of species based on their time-of-flight. On-demand concentration pulse generation, separation, and detection are all integrated in a miniaturized platform.
用于电化学测量的纳米通道和电极具有极高的表面积与体积比，即使是微弱的表面相互作用也能引起高度敏感的响应。在这里，我们利用外球型氧化还原物种的电位依赖性可逆吸附来在空间和时间上调制纳米通道中它们的浓度，在有对流流条件下。诱导的浓度变化以依赖于物种的速度向下游传播。这使得人们能够根据飞行时间对纳摩尔级的物种进行安培区分。按需浓度脉冲的产生、分离和检测都集成在一个小型化平台中。
