Figure 1: [A] Scattering intensity as a function of scattering angle for the 20 base-pair double-labeled (blue), single-labeled (red, magenta; indistinguishable), and unlabeled (cyan) DNA duplexes. The intensity of the double-labeled sample has been scaled by a factor of 1/2 to aid visual comparison. The pattern of scattering interference between the two nanocrystal labels (black) is obtained b...

Background: Natamycin belongs to a large group of naturally occurring polyene antifungal antibiotics derived from Streptomyces natalensis. has restrictive pharmaceutical role because its extremely low aqueous solubility, which severely reduces the bioavailability drug. To improve absorption drug, nanocrystals natamycin were prepared and incorporated into in situ gel.
 Aim: solubility by pr...

Membrane osmometry is used to measure osmotic pressures of dilute solutions containing quasi-spherical CdSe nanocrystals covered with polymer brushes in toluene in the range 31 to 45°C. Osmotic-pressure data, as a function of nanocrystal concentration, yield the molecular weight and the osmotic second virial coefficient of the nanocrystals; the latter is related to the potential of mean force b...

Supported catalysts are widely used in industry and can be optimized by tuning the composition and interface of the metal nanoparticles and oxide supports. Rational design of metal-metal oxide interfaces in nanostructured catalysts is critical to achieve better reaction activities and selectivities. We introduce here a new class of nanocrystal tandem catalysts that have multiple metal-metal oxi...

We report on the correlation between the nanocrystal and surface alloy properties with the bimetallic composition of gold-platinum(AuPt) nanoparticles. The fundamental understanding of whether the AuPt nanocrystal core is alloyed or phasesegregated and how the surface binding properties are correlated with the nanoscale bimetallic properties is important not only for the exploitation of catalyt...

We present the first semiconductor nanocrystal films of nanoscale dimensions that are electrically conductive and crack-free. These films make it possible to study the electrical properties intrinsic to the nanocrystals unimpeded by defects such as cracking and clustering that typically exist in larger-scale films. We find that the electrical conductivity of the nanoscale films is 180 times hig...

The electrostatic charge and photoionization characteristics of 5-nm CdSe nanocrystals were directly observed with electrostatic force microscopy (EFM) in dry air at room temperature. Measurements were made on individual nanocrystals, as well as on those in self-assembled rafts. Nanocrystals are initially charge neutral if protected from sources of light. However, over a few weeks some nanocrys...

Doping is extremely important for controlling the electronic conductivity of bulk semiconductors. However, very few examples exist where impurities that have been incorporated into colloidal semiconductor nanocrystals affect their electronic properties. Here we will discuss the challenges in this area as well as recent progress. In particular, we will describe an approach to lightly dope semico...

The catalytic activity of metal nanocrystals is mainly tuned through the control of their shapes and sizes. However, the shapes and sizes of many metal nanocrystals are difficult to control and therefore their catalytic activity is hard to tune. Here, we demonstrate another approach, using differently charged surfactants, for tuning the catalytic activity of metal nanocrystals. Au and Pd nanocr...

Exchange of initial, predominantly stearate ligands for pyridine in the first step and butylamine (BA) or 11-mercaptoundecanoic acid (MUA) in the second one was studied for alloyed quaternary Cu-In-Zn-S nanocrystals. The NMR results enabled us to demonstrate, for the first time, direct binding of the pyridine labile ligand to the nanocrystal surface as evidenced by paramagnetic shifts of the th...