The appearance of drug-resistant (especially, multidrug-resistant (MDR)) tumor cells is a major obstacle to the success of chemotherapy; thus, the development of effective anti-MDR agents plays an important role in the tumor therapy. In this report, the considerable effect of nano-TiO2 and UV illumination on the drug resistance of target cancer cells has been explored, and the fresh evidence from the fluorescence spectroscopy and microscopy as well as electrochemical studies demonstrates the significant enhancement effect of nano-TiO2 to the drug uptake by drug-resistant leukemia cells. Besides, it is also observed that the combination of the nano-TiO2 and UV irradiation with the accompanying anticancer drug daunorubicin could provoke some considerable changes of the cell membrane of the target leukemia cells, which indicates that nano-TiO2 could not only increase the drug accumulation in target cancer cells, but also act as an effective anti-MDR agent to inhibit the relative drug resistance.

A non-dense long-chain tethered bipyridinium monolayer linked to an electrode support is reversibly retracted and attracted from and to the electrode respectively by the applied potential. The "molecular machinery" functions of the monolayer are probed by chronoamperometry and contact angle measurements.

Three kinds of magnetic nanoparticle, tetraheptylammonium capped nanoparticles of Fe3O4, Fe2O3 and Ni have been synthesized, and the synergistic effect of these nanoparticles on the drug accumulation of the anticancer drug daunorubicin in leukaemia cells has been explored. Our observations indicate that the enhancement effect of Fe3O4 nanoparticles is much stronger than that of Fe2O3 and Ni nanoparticles, suggesting that nanoparticle surface chemistry and size as well as the unique properties of the magnetic nanoparticles themselves may contribute to the synergistic enhanced effect of the drug uptake of targeted cancer cells.

Asymmetrical deformation of an aqueous electrolyte droplet bridging two bipyridinium-modified Au-electrodes is achieved upon the application of voltages resulting in the selective reduction and oxidation of the bipyridinium units on the two electrodes. The different contact angles at the right and left sides of the droplet originate from the electrochemically controlled changes of the wetting properties of the modified electrodes. The reversible and repeatable formation of an electrolytic contact between a side Ptwire electrode and the respective bottom Au-electrode is controlled by the voltage applied between the two bottom Au-electrodes.

The electrochemical redox-induced contact angle changes of hemoglobin droplets in the absence and presence of tetraheptylammonium-capped Fe3O4 nanoparticles have been explored by using in situ electrochemical contact angle measurements. The results indicate that the electrochemical redox process may lead to some structure changes of hemoglobin (Hb), which could further induce the hydrophobic-to-hydrophilic changes of the relative droplets. Our observations demonstrate that hemoglobin could self-assemble on the surface of the functionalized Fe3O4 nanoparticles as Hb–Fe3O4 nanocomposites, which may contribute to much more significant change of the electrochemical redox-induced contact angle values than that with free nano-Fe3O4. These results suggest that in situ electrochemical contact angle measurements could be readily applied as a new and convenient method to detect some specific biological process.