Chemical Sensing and Chemoresponsive Pumping with Conical-Pore Polymeric Membranes

Chemical Sensing and Chemoresponsive Pumping with Conical-Pore Polymeric Membranes

Blog Article

Synthetic membranes containing asymmetrically shaped pores have been shown to rectify the ionic current flowing through the membrane.Ion-current rectification means that such membranes produce nonlinear current−voltage curves analogous to those observed with solid-state diode rectifiers.In order to observe this ion-current rectification phenomenon, the asymmetrically shaped pores must have pore-wall surface charge.

Pore-wall surface charge Dog also allows for electroosmotic flow (EOF) to occur through the membrane.We have shown that, because ion-current is rectified, EOF is likewise rectified in such membranes.This means that flow through the membrane depends on the polarity of the voltage applied across the membrane, one polarity producing a higher, and the opposite producing a lower, flow rate.

As is reviewed here, these ion-current and EOF rectification phenomena are being used to develop new sensing technologies.Results obtained from Deodorant an ion-current-based sensor for hydrophobic cations are reviewed.In addition, ion-current and EOF rectification can be combined to make a new type of device—a chemoresponsive nanofluidic pump.

This is a pump that either turns flow on or turns flow off, when a specific chemical species is detected.Results from a prototype Pb2+ chemoresponsive pump are also reviewed here.