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Four types of water-soluble quantum dots (QDs) grafted with different organic coating layers were fabricated, and their sensitivities for hypochlorite/hypochlorous acid (HClO) were examined. It was found that QDs with HClO reactive (methylamino and sulphide groups) coating layers exhibited a protective effect on HClO quenching of QD fluorescence, whereas QDs with hydrocarbon and carboxylate coating layers showed least protection to QD fluorescence quenching by HClO and, thus, has the highest sensitivity for the detection of HClO. The QDs with carboxylate coating layers (QDs-poly-C[O.sub.2.sup.-]) was successfully applied to the quantification of HClO in tap water. The excellent selectivity of the QDs-poly-C[O.sub.2.sup.-] toward hypochlorite against other reactive oxygen species allowed us to monitor myeloperoxidase activity. Finally, the QDs-poly-C[O.sub.2.sup.-] was also used for the detection of hypochlorite in HL60 cells by fluorescent imaging. Hence, QD-poly-C[O.sub.2.sup.-] exhibits great promise as a selective and sensitive HClO probe in chemical and biological systems. 10.1021/ac101929q

In this paper, Mn-doped ZnS quantum dots (QDs) capped by a molecularly imprinted polymer (MIP) were synthesized. The results showed a high selectivity of the MIP-capped Mn-doped ZnS QDs toward the template molecule (4-nitrophenol) by QD fluorescence quenching. The application of MIP-capped Mn-doped ZnS QDs to the chemiluminescence (CL) system was also studied using a KI[O.sub.4]-[H.sub.2][O.sub.2] system. This application combines the good selectivity of MIP with the high sensitivity of CL. The linear range of this CL system is from 0.1 to 40 [micro]M, and the detection limit (DL) for 4-nitrophenol in the water can reach 76 nM. The method was also used in the real water samples, and the recoveries can fall in the range of 91-96%. 10.1021/ac101510b

The luminescence of CdSe/ZnS QDs is quenched via electron transfer by hemin/G-quadruplex associated with the particles. This phenomenon is implemented to develop DNA sensors or aptasensers by tailoring hairpin-functionalized QDs that generate the hemin/G-quadruplex quenchers upon sensing of the respective analytes. 10.1021/ac101456x

A versatile immunosensor using a CdTe quantum dots (QDs) coated silica nanosphere (Si/QD) as a label was proposed for ultrasensitive detection of a biomarker. In this approach, silica nanospheres with good monodispersity and uniform structure were employed as the carrier for immobilization of QDs and antibodies. Rabit IgG served as a model protein to demonstrate the performance of the immunosensor. Goat antirabbit IgG antibody was covalently bound to CdTe QDs on the surface of silica nanospheres. CdTe QDs coated with a silica nanosphere label (Si/QD/Ab2) were attached onto the gold electrode surface through a subsequent 'sandwich' immunoreaction. This reaction was confirmed by scanning electron microscopic (SEM) and fluorescence microscopic images. Due to signal amplification from the high loading of CdTe QDs, 6.6- and 5.9-fold enhancements in electrochemiluminescent (ECL) and square-wave voltammetric (SWV) signals for IgG detection were achieved compared to the unamplified method. The detection limits for IgG were 1.3 and 0.6 pg [mL.sup.-l] for ECL and SWV measurements, respectively. The resulting versatile immunosensor possesses high sensitivity, satisfactory reproducibility and regeneration, and good precision. This simple and specific strategy has vast potential to be used in other biological assays. 10.1021/ac100558t

A novel electrocbemiluminescent (ECL) sensing system was constructed for low-potential detection of metal ion by immobilizing surface-unpassivated CdTe quantum dots (QDs) on a glassy carbon electrode. The surface-unpassivated CdTe QDs were prepared using meso-2,3-dimercaptosuccinic acid (DMSA) as a stabilizer to cap CdTe QDs and characterized with scanning electron micrograph and X-ray photoelectron spectroscopy. The immobilized QDs showed a strong cathodic ECL emission peak at -0.87 V with an onset potential at -0.64 V (vs Ag/AgCl/ saturated KCl) in air-saturated, pH 9.0 HC1--Tris buffer. On the basis of the competition of metal ion to the stabilizer, the quenching effect of metal ion on ECL emission was observed, which led to a sensitive chemical sensing application. Using cupric cation as a model analyte, the sensor showed a linear range from 5.0 nM to 7.0 [micro]M with a detection limit of 3.0 nM and had been successfully applied in the detection of copper in human hair. It could be extended to detect other metal ions with stronger metal--S interaction than with the Cd--S bond. As an example, the sensor could be used to detect [Hg.sup.2+] down to 1.4 nM. The bidentate chelate QD-basod sensor exhibited a promising platform for rapid detection of cations with strong metal--S interaction and could be further applied for development of other low-potential electrochemical sensing systems. 10.1021/ac100315a

As a kind of Na-incorporating control method, NaF co-evaporation or soda-lime glass thin films (SLGTFs) are useful to improve the photovoltaic performance of Cu(In, Ga)[Se.sub.2] (CIGS) cells fabricated on low-Na substrates. X-ray diffraction (XRD) patterns and scanning electron microscope pictures demonstrate that the grain size of CIGS thin film is reduced with the addition of Na. In addition, a variance of the preferred orientation is found by XRD patterns in terms of SLGTF samples. By a use of 100 nm thick SLGTF as a Na source, the best CIGS solar cell with an efficiency of 13.42% has been obtained. [c] 2010 Optical Society of America OCIS codes: 160.6000, 310.6845.

Integrating various enzymes with nanomaterials provides various nanohybrids with new possibilities in biosensor applications. Furthermore, the enzymatic activity and stability are also improved due to the large surface area of nanomaterials. Here we report the conjugation of glucose oxidase (GOD) onto phosphorescent Mn-doped ZnS quantum dots (QDs) using 1-ethyl-3-(3-dimethylaminoprepy)carbodiimide (EDC)/N-hydroxysuccinimide (NHS) as coupling reagents for glucose biosensing based on the effective quenching of the room temperature phosphorescence (RTP) of Mn-doped ZnS QDs by the [H.sub.2][O.sub.2] generated from GOD-catalyzed oxidation of glucose. The obtained bioconjugate not only provided improved enzymatic performance with Michaelis-Menten constant of 0.70 mM but also favored biological applications because the phosphorescent detection mode avoided the interference from autofluorescence and scattering light from the biological matrix. In addition, the GOD-conjugated Mn-doped ZnS QDs showed better thermal stability in the temperature range of 20-80[degrees]C. The GOD--Mn-doped ZnS QDs based RTP sensor for glucose gave a detection limit of 3 [micro]M and two linear ranges from 10 [micro]M to 0.1 mM and from 0.1 to 1 mM. The developed biosensor was successfully applied to the determination of glucose in real serum samples without the need for any complicated sample pretreatments. 10.1021/ac902531g

X-ray diffraction, electrical resistivity, magnetization, specific heat, and thermoelectric power measurements are presented for single crystals of the new filled skutterudite compound Ce[Os.sub.4][As.sub.12], which reveal phenomena that are associated with f-electron-conduction electron hybridization. Valence fluctuations or Kondo behavior dominates the physics down to T ~ 135 K. The correlated electron behavior is manifested at low temperatures as a hybridization gapinsulating state. The small energy gap [[DELTA].sub.1]/[k.sub.B] ~ 73 K, taken from fits to electrical resistivity data, correlates with the evolution of a weakly magnetic or nonmagnetic ground state, which is evident in the magnetization data below a coherence temperature [T.sub.coh] ~ 45 K. Additionally, the low-temperature electronic specific heat coefficient is small, [gamma] ~ 19 mJ/mol [K.sup.2]. Some results for the nonmagnetic analogue compound La[Os.sub.4][As.sub.12] are also presented for comparison purposes. Kondo insulator | rare earth compound

The current-voltage (I-V) characteristics under forward biases obtained in small size (In, Ga)N-GaN multiquantum-well diodes are discussed. Findings reveal the capability of the diodes in detecting optical powers in the pW range under barrier illumination.

The molecular and electronic structures of (Zn4(mu4-S)(mu-S2As(CH3)2)6) of the novel Cd complex (Cd4(mu4-S)(mu-S2As(CH3)2)6) have been studied with x-ray diffraction measurements, electrospray mass and UV absorption spectrometries and density functional computations. Results indicate that the unit cell has four independent molecules and four solvent molecules. Each independent unit has a central mu4-S coordinated to four Zn ions.

The theoretical study of high electric field transport in n-Ga(sub 1-x)Al(sub x)As semiconductor alloys for composition x range from 0 to 0.5, reveal that a close to linear decrease of peak velocity with an increase in the alloy composition x and an absence of the onset of negative differential mobility at x greater than 0.35 is present. The calculations are based on a Maxwellian approach for the 3 valley conduction band model. The calculation invokes an expression for the alloy scattering probability having no fitting parameters.

The matrix isolation technique is used in the infrared spectroscopic characterization of the complexes TiCl4 with PH3 and AsH3. Pyrolysis tests are carried out on the complexes to analyze their band structures and vibrational modes. Results show that the the ability of PH3 and AsH3 to donate electron density to TiCl4 is strongly dependent on their level of basicity.

Gold growth on CdS nanorods and on seeded CdSe/CdS nanorods with and without illumination at different temperatures is analyzed and two competing mechanisms like thermal and light-induced growth are identified. Light-induced growth has led to selective deposition of gold on one end of the rods and the growth under illumination with decreased temperature has provided a highly selective synthesis of hybrid semiconductor nanorods with a single gold tip.

The solution-liquid-solid (SLS) mechanism is used to synthesize for the first time ternary CuIn[Se.sub.2] nanowires. The obtained CuIn[Se.sub.2] nanowires are strong light absorbers from the near-infrared through the visible and ultraviolet spectral regions could be used as new soluble and processable 'building blocks' for applications in solar-light harvesting.

A wide variety of nanostructure shapes are observed for GaN under different growth conditions and Wulff's plot and kinetic Wulff's plot is used for GaN under thermodynamic equilibrium and under various kinetic conditions. Equilibrium and nonequilibrium faceted geometry of nanostructures are predicted by numerical simulations by using level set methods and the kinetic Wulff's plot.

The nature of nanoscratching as a lithographic method for site-selective generation of dislocations is examined so that it can be used in the growth of nanostructures. The results have shown that the grown of nanostrucutres are dependent on the direction of the nanoscratch.

The conventional solid state reactions method is used for preparing semiconductors of [Na.sub.1-x][La.sub.x][Ta.sub.1-x][Cr.sub.x][O.sub.3]. [H.sub.2] generation under visible light irradiation is obtained with the tuning of band structures of [Na.sub.1-x][La.sub.x][Ta.sub.1-x][Cr.sub.x][O.sub.3] and the visible light harvesting as well as the photocatalysis is discussed based on the electronic structures.

The combination of many thin layers of constituent materials is described as digital metamorphic alloy (DMA). Lattice-constant grading from GaAs to InP is carried out by using both the DMA concept and a hybrid analog-buffer/DMA approach.

The effect of the dot size and shape on the electron and hole energy states and on transition energies is examined by using a unifying model of the semiconductor band structure. The electron energy spectra are obtained for three-dimensional small InAs/GaAs quantum dots of many different truncated shapes of different geometries.

The article explains the various effects of catalyst proximity on the growth rate of the Si nanowires that are formed by using the vapor-liquid-solid mechanism. An increase in the concentrations of the Au-catalyst particles on the water surface is shown to lead to an increase in the growth rate of the nanowires.

The conductance method is employed to study the minority, as well as majority carrier responses taking place in the Ge metal-insulator-semiconductor (MIS) interface traps. The discussed MIS capacitors, as well as the electron capture cross section are both shown to be completely independent of the energy.

The various current oscillations occurring in the current-voltage characteristics in a wide graphene sheet are analyzed. The carrier transport of the system is shown to be highly dependent on the two spatial components of the wave vector.

Several temperature dependent Hall effect measurements are conducted to determine the various defects observed in the virgin hydrothermally grown n-type ZnO samples. The results prove that the electron mobility in the compounds is affected by mainly two phenomenon, namely the ionized impurity-scattering and optical photon scattering.

A systematic theoretical study of the Cerenkov acoustic-phonon emission from a polar semiconductor such as GaAs driven by dc electric field is presented. The electron velocity which exceeded the sound velocity in GaAs even when electrons are still in the linear response regime indicated the possibility for easy observation of the Cerenkov phonon emission in GaAs-based electron gas systems.

A systematical study was conducted to explore the force dependence of conductive atomic force microscopy on n-type Si and n-type GaAs. A sudden change in the Schottky barrier increase with tip force was attributed to the [Gamma]-x band crossover in GaAs.

A metal-insulator-semiconductor (MIS) structure with a gate insulator is described based on an HfNO-HfTiO nanolaminate stack that has a total thickness of 5 nm. Lower effective oxide thickness (EOTs) is predicted with the use of thicker HfN sublayers, with a significant nitrogen concentration that will result in stoichiometric HFSiON.

The construction of a complete adlayer of organic nanolines by supramolecular self-assembly on Si(111)-B [square root of 3x][square root of 3R30 degree] surface at room temperature is described. The new method provides a versatile and easy approach to extend the supramolecular organization developed on metallic substrate to semiconductive substrates at room temperature.

The synthesis of ternary Cu-In-S semiconductor nanocrystals with tunable [Cu]/[In] composition by a hot-injection method is reported. The nanocrystals might be used as a new class of suitable materials for high-efficiency solar cell fabrication.

Oxide semiconductor alloys of x[(LiGa[O.sub.2]).sub.1/2]-(1-x)ZnO are synthesized by a standard solid state reaction. The alloy is a good candidate for the barrier material of the ZnO-based heterostructures and UV-transparent electrodes.

The band offsets of yttrium oxide ([Y.sub.2][O.sub.3]) on various relaxed and strained semiconductor substrates, such as silicon, germanium and silicon germanium, are described. Interfacial layer model is used for describing the band offsets.

The structural and magnetic properties are correlated in order to analyze the formation of transition metal (Co, Ni) and Mn-silicide nanocrystals in semiconductors. The difficulties in probing nanocrystals of small amount are generalized by using x-ray diffraction (XRD) method.

The electrical, structural and chemical properties of twisted yarns of metal-oxide nanofibers, which are fabricated by using a modified electrospinning method, are examined. These zinc oxide and nickel oxide yarns have one macroscopic dimension for handling while retaining some of the properties of nanofibers.

The effect of annealing atmosphere of Ar, [N.sub.2] or [O.sub.2] on the recombination activity of copper (Cu) precipitates in conventional Czochralski (CZ) silicon and nitrogen-doped CZ (NCZ) silicon wafers are examined. The results have shown that the Cu precipitates formed under the same conditions have possessed stronger recombination activity in CZ silicon than in NCZ silicon.

Larger volume cadmium zinc telluride (CZT) crystals are developed by using high-resolution radiation detectors based on the traveling heater method. The results have shown that the theoretical energy resolution limit can be achieved with careful material selection by using infrared and high-quality fabrication processes.

Process-induced positive charging (PIPC) in Hf-based gate stacks is examined. PIPC is enhanced by nitridation, although it can be seen in some Hf-based gate stacks without nitridation.

Time-of-flight (TOF) measurements are performed on n-type Ti[O.sub.2]/p-type CuIn[S.sub.2] heterojucntions. The neutrality level of these interface states is above the valence band on CuIn[S.sub.2].

The formation of atomic-scale graded structure in selenium-tellurium semiconductor is studied by using a strong gravitational field. The observed crystals growth along the c axes of the hexagonal structure perpendicular to the direction of gravity and diffusion coefficient of sedimentation more than 100 indicate the existence of a different diffusion mechanism.

The effect of [(N[H.sub.4]].sub.2][S.sub.x] treatment on the surface electronic properties of indium tin oxide (ITO)-doped ZnO films is examined. The treatment is found to be helpful in the uniform deposition of the organic semiconductor on ITO-doped ZnO surfaces due to increased surface energy and improve the efficiency of organic devices.

A method is developed to determine the concentration of oxygen and carbon impurities in silicon particle detectors by analyzing the carbon interstitial annealing kinetics using deep level transient spectroscopy data (DLTS).

Research has been conducted on organic-inorganic hybrid [CH (sub)3 (CH (sub)2) (sub)11 NH (sub)3]SnI (sub)3. The authors report that this hybrid presents a lamellar structure with a Sn-I framework isotypic to thet of MoO (sub)3, and that it offeres a new type of solution-processable Sn-I for application in semiconductors.

The single-band envelope-function model in the entire Brillouin zone for electronic structure calculation of nanostructures that involve semiconductors with one or more significant valleys in the conduction band was explored. This model is used for modeling the nanostructures and nanodevices based on Si and other materials.