The TiO 2 nanoparticle thin films have been sensitized in situ with CdS nanoparticles. The SPS measurement showed that large surface state density was present on the TiO 2 nanoparticles and the surface state can be ef...
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The TiO 2 nanoparticle thin films have been sensitized in situ with CdS nanoparticles. The SPS measurement showed that large surface state density was present on the TiO 2 nanoparticles and the surface state can be efficiently decreased by sensitization as well as selecting suitable heat treatment. Both the photocurrent response and the charge recombination kinetics in TiO 2 thin films were strongly influenced by trapping/detrapping of surface states. The slow photocurrent response of TiO 2 nanoparticulate thin films upon the illumination was attributed to the trap saturation effects. The semiconductor sensitization made the slow photoresponse disappeared and the steadystate photocurrent value increased drastically, which suggested that the sensitization of TiO 2 thin films with CdS could get a better charge separation and provide a simple alternative to minimize the effect of surface state on the photocurrent response.
Dip-pen nanolithography(DPN) has been developed to pattern monolayer film of various molecules in submicrometer dimensions through the controlled movement of ink-coated atomic force microscopy(AFM) tip on a desired su...
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Dip-pen nanolithography(DPN) has been developed to pattern monolayer film of various molecules in submicrometer dimensions through the controlled movement of ink-coated atomic force microscopy(AFM) tip on a desired substrate, which makes DPN a potentially powerful tool for making the functional nanoscale devices. In this letter, using direct-write dip-pen nanolithography to generate nanoscale patterns of poly-L-lysine on mica was described. Poly-L-lysine molecules can anchor themselves to the mica surface through electrostatic interaction force, so stable poly-L-lysine patterns, such as square, line, circle and cross, could be obtained on freshly cleaved mica surface. From AFM image of the patterned poly-L-lysine nanostructures on mica, we know that poly-L-lysine was flatly bound to the mica surface. These oriented patterns of poly-L-lysine on mica can provide the prospect of building functional nanodevices and offer new options for this technique in a variety of other significant biomolecules.
A novel method of colorimetric assay for determining cis-Pt (cis-diammino-dichloroplatinum Ⅱ) was found by the binding affinities between cis-Pt and DNA based on the change of surface plasmon resonance band of gold n...
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A novel method of colorimetric assay for determining cis-Pt (cis-diammino-dichloroplatinum Ⅱ) was found by the binding affinities between cis-Pt and DNA based on the change of surface plasmon resonance band of gold nanoparticles. The red-shift of the maximum band of the surface plasmon resonance band of gold nanoparticles increased linearly with the logarithm of the cis-Pt concentration from 40 to 2000 nmol/L and the detection limit is 40 nmol/L when the concentration of gold nanoparticles is 4 nmol/L. The colorimetric readout can be visualised with the naked eyes.
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