Switching Properties of Monolayer Systems

Mrksich and coworkers [150] demonstrated even more sophisticated switchable surfaces where cells could be sequentially released and reattached. A SAM that 

These types of switchable electrode surfaces have been used to selectively pattern two different cell populations onto a surface [151] and additionally these surfaces can selectively release different cells at different applied potentials [152]. However, it is important to recognize that electrochemically switching a surface from inactive to conjugation and active to conjugation has been well explored with nitro-terminated aryl diazonium salts. In such studies, the application where very anodic potential resulted in a six-electron reduction to an amine [139], to which proteins could be attached [153-155]. The key difference is that the interaction of the biological medium with the surface is controlled by the presence of the antifouling layer. In many ways these electrode surfaces developed by Mrksich and coworkers [150-152, 156] are very similar to the antifouling surfaces with molecular wires discussed in Section 1.4.2 [131, 132, 138, 142]. In both cases the electrode is 

Control and Enhancement of Electrochemical Reactions using Magnetic Nanostructures on Electrodes 

Willner and coworkers [168] demonstrated the applicability of this method for a range of applications including the magneto-switching of DNA hybridization and polymerization for programmed DNA chips, of photocatalytically activated reactions using CdS nanoparticles for optobioelectronic systems [169], and of quinone oxidation and reduction for write-read-erase information storage systems [170]. 

An exciting advancement of the magneto-switching concept involved the demonstration by Wang and coworkers [171] of the ability to use magnetic fields to control electrochemical reactivity on electrodes in comparison to previous demonstrations 

Lahann, S. Mitrogotri.T.N.Tran, H. Kaido, J. Sundaram, I.S. Choi, 

---