Accelerated Charge Transfer in the AgInS-Polymer Layer-by-Layer Films.

In this work, the luminescence properties of AgInS colloid nanoparticles in solution and in films were investigated and compared. Decay time of fast and slow relaxation processes differ by about an order of magnitude. Both components are significantly reduced in films compared to the corresponding contributions in colloids that hint towards charge carrier transfer between AgInS particles enhanced in the films.

Design and application of potentiometric sensors for the determination of mefenamic and phenylanthranilic acids.

Characteristics, performance and applications of potentiometric membrane sensors are described for the determination of mefenamic and phenylanthranilic ions. Ion associates of mefenamic, ClO, and phenylanthranilic ions with crystal violet (counter-cation) as ion exchange sites have been used as ionophores in the plasticized one- and two-layer membrane ion-selective electrodes. The LOD is reported to be 8.

Two-step light conversion with quantum dots inside non-linear crystals.

Up-conversion of infrared (IR) to visible light is demonstrated via an unconventional two-step process combining second harmonic generation with photoluminescence. This is achieved in a composite material formed by single crystals of KHPO (KDP), in which CdTe/CdS quantum dots (QDs) are embedded during a crystal growth. The second harmonic generation from the IR laser frequency in KDP takes place, and then, generated light is absorbed by QDs and luminescence is emitted.

Influence of the KBr matrix on the luminescence properties of CdTe quantum dots.

The investigation of the luminescence properties of CdTe/KBr composites with encapsulated quantum dots (QDs) of different sizes was performed and the influence of the KBr matrix on the luminescence properties of CdTe QDs was studied. Encapsulation of nanoparticles by a solid matrix caused a bathochromic shift in the luminescence peak and the shift value was the larger the smaller the size of the quantum dots. Interband quantum transition theory was used to explain the influence of the matrix on the luminescence properties of the capsulated CdTe QDs.

Synthesis and Properties of Water-Soluble Blue-Emitting Mn-Alloyed CdTe Quantum Dots.

In this work, we prepared CdTe quantum dots, and series of CdMnTe-alloyed quantum dots with narrow size distribution by an ion-exchange reaction in water solution. We found that the photoluminescence peaks are shifted to higher energies with the increasing Mn content. So far, this is the first report of blue-emitting CdTe-based quantum dots.

Synthesis of Au-CdS@CdSe Hybrid Nanoparticles with a Highly Reactive Gold Domain.

We propose a novel route to synthesize semiconductor-gold hybrid nanoparticles directly in water, resulting in much larger gold domains than previous protocols (up to 50 nm) with very reactive surfaces which allow further functionalization. This method advances the possibility of self-assembly into complex structures with catalytic activity toward the reduction of nitro compounds by hydrides. The large size of these gold domains in hybrid particles supports efficient light scattering at the plasmon resonance frequency, making such structures attractive for single-particle studies.

Influence of the Shell Thickness and Ratio Between Core Elements on Photostability of the CdTe/CdS Core/Shell Quantum Dots Embedded in a Polymer Matrix.

This paper reports a study of photooxidation and photomodification processes of the CdTe/CdS quantum dots embedded in a polymer matrix under ambient condition. During the first few minutes of irradiation, the quasi-inverse increase in photoluminescence intensity has been observed indicating the passivation of the nanocrystal surface traps by water molecules. A prolonged irradiation of the polymer film containing CdTe/CdS quantum dots leads to a significant decrease in the photoluminescence intensity together with the "blue shift" of the photoluminescence peak energy associated with quantum dot photooxidation.

Highly sensitive plasmonic silver nanorods.

We compare the single-particle plasmonic sensitivity of silver and gold nanorods with similar resonance wavelengths by monitoring the plasmon resonance shift upon changing the environment from water to 12.5% sucrose solution. We find that silver nanoparticles have 1.

Light-controlled one-sided growth of large plasmonic gold domains on quantum rods observed on the single particle level.

We create large gold domains (up to 15 nm) exclusively on one side of CdS or CdSe/CdS quantum rods by photoreduction of gold ions under anaerobic conditions. Electrons generated in the semiconductor by UV stimulation migrate to one tip where they reduce gold ions. Large gold domains eventually form; these support efficient plasmon oscillations with a light scattering cross section large enough to visualize single hybrid particles in a dark-field microscope during growth in real time.

Synthesis of rod-shaped gold nanorattles with improved plasmon sensitivity and catalytic activity.

We prepared rod-shaped gold nanorattles solid gold nanorods surrounded by a thin gold shell using a galvanic replacement process starting with silver-coated gold nanorods. These structures are very promising candidates for catalytic applications and optimized plasmon sensors. They combine the advantages of rods (low plasmon resonance frequency, large polarizability, small damping) with the high surface area of hollow structures.

Mapping the polarization pattern of plasmon modes reveals nanoparticle symmetry.

We study the wavelength and polarization dependent plasmon resonances of single silver and gold nanorods, triangles, cubes, and dimers with a novel single particle spectroscopy method (RotPOL). In RotPOL, a rotating wedge-shaped polarizer encodes the full polarization information of each particle within one image. This reveals the symmetry of the particles and their plasmon modes, allows analyzing inhomogeneous samples and the monitoring of particle shape changes during growth in situ.

Plasmonic focusing reduces ensemble linewidth of silver-coated gold nanorods.

Silver coating gold nanorods reduces the ensemble plasmon line width by changing the relation connecting particle shape and plasmon resonance wavelength. This change, we term "plasmonic focusing", leads to less variation of resonance wavelengths for the same particle size distribution. We also find smaller single particle linewidth comparing resonances at the same wavelength but show that this does not contribute to the ensemble linewidth narrowing.