Anal Chem. 2012 Aug 21;84(16):6926-9. doi: 10.1021/ac301791e. Epub 2012 Aug 7.
Surface modification will change the surface charge density (SCD) at the signal-limiting region of nanochannel devices. By fitting the measured i-V curves in simulation via solving the Poisson and Nernst-Planck equations, the SCD and therefore the surface coverage can be noninvasively quantified. Amine terminated organosilanes are employed to chemically modify single conical nanopores. Determined by the protonation-deprotonation of the functional groups, the density and polarity of surface charges are adjusted by solution pH. The rectified current at high conductivity states is found to be proportional to the SCD near the nanopore orifice. This correlation allows the noninvasive determination of SCD and surface coverage of individual conical nanopores.
表面修饰会改变纳米通道器件信号限制区域的表面电荷密度（SCD）。通过求解泊松和能斯特-普朗克方程对模拟测量的 i-V 曲线进行拟合，可以非侵入性地定量 SCD 以及表面覆盖率。采用胺封端的有机硅烷对单锥形纳米孔进行化学修饰。通过官能团的质子化-去质子化来确定，表面电荷的密度和极性可以通过溶液 pH 值进行调节。在高电导率状态下的整流电流被发现与纳米孔口附近的 SCD 成正比。这种相关性允许对单个锥形纳米孔的 SCD 和表面覆盖率进行非侵入性测定。
