A new non-enzymatic glucose sensor based on copper/porous silicon nanocomposite

A new electrochemical sensor for the simultaneous determination of acetaminophen and codeine based on porous silicon/palladium nanostructure

Here, a non-enzymatic amperometric sensor is fabricated for glucose detection based on nickel nanoparticles supported on porous silicon flour. A facile procedure was introduced for the in-situ electroless assembling of nickel nanoparticles on porous silicon (PS) flour without using any reducing agent. Briefly, Ni@PSnanocompositewaspreparedthroughthechemicalreductionofNi2(Her)+ ions and oxidation of the surface of Si atoms in ammonium fluoride solution. The formation of the Ni@PS nanocomposite was confirmed by scanning electron microscopy (SEM), X-ray diffraction spectroscopy (XRD), energy dispersive spectroscopy (EDS) and FT-IR spectroscopy as well as cyclic voltammetry (CV). The synthesized nanocomposite was employed as an electrode material for non-enzymatic glucose (Gl) sensing using carbon paste electrode (CPE). The prepared amperometric sensor exhibited a wide linear range of 2.0–5000 μmol L−1 with a low limit of detection (0.2 μmol L−1) as well as high stability and fast response time (<3 s). Also, no significant interference was observed from potentially interference species such as dopamine, ascorbic acid, uric acid and Cl− ions. The excellent applicability of the proposed sensor for determination of Gl in human blood serum with good accuracy and reproducibility made Ni@PS nanocomposite promising for the development of effective electrochemical non-enzymatic Gl sensor.

Nickel nanoparticles supported on porous silicon flour, application as a non-enzymatic electrochemical glucose sensor

Pt nanoparticles supported on porous silicon (PSi) flour was synthesized by a simple in-situ redox reaction between PtCl62− and PSi, in hydrofluoric acid solution. The components and morphological properties of Pt/PSi nanocomposites were investigated by means of scanning electron microscopy, X-ray diffraction spectroscopy, energy dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, cyclic voltammetry and electrochemical impedance spectroscopy. Pt/PSi nanocomposite in carbon ionic liquid electrode (CILE) has synergetic effect on the oxidation of morphine and codeine. Simultaneous determination of morphine and codeine were performed using the proposed sensor by means of adsorptive striping voltammetry. Under the optimum conditions, the oxidation current responses of morphine and codeine were linear in the concentration range of 0.10–25.0 μmol L−1. The detection limits of 30.0 and 20.0 nmol L−1 were achieved for morphine and codeine, respectively. The electrochemical sensor has high sensitivity toward the analytes with a good reproducibility (due to the high synergetic activity of Pt nanoparticles and good antifouling properties of the ionic liquid). To check the applicability of the sensor, the proposed sensor was used for the simultaneous determination of morphine and codeine in biological fluids with satisfactory results.

Simultaneous determination of morphine and codeine using Pt nanoparticles supported on porous silicon flour modified ionic liquid carbon paste electrode

Facile synthesis of Pt-Cu@silicon nanostructure as a new electrocatalyst supported matrix, electrochemical detection of hydrazine and hydrogen peroxide

Thin-film poly-crystalline silicon (poly c-Si) on glass obtained by crystallization of an amorphous silicon (a-Si) film is a promising material for low cost, high efficiency solar cells. Our approach to obtain this material is to crystallize a-Si films on glass by solid phase crystallization (SPC). As the grain size of SPC poly c-Si films will be smaller than that of multi-crystalline wafers, lower solar cell efficiencies are expected for this technology. Despite the smaller grain size, a 2-micron-thick polycrystalline silicon solar cell with light trapping was shown to have a conversion efficiency of more than 10% [1]. Obtainable efficiencies up to 15% are expected for solar cells made using SPC of a-Si:H films. Expanding thermal plasma chemical vapor deposition (ETP-CVD) was used to prepare hydrogenated a-Si films; this technique is chosen because the deposition rates are much higher than with plasma enhanced CVD. A-Si:H films with different hydrogen contents were annealed using temperatures ranging from 500°C to 700°C. The evaluation of the films after annealing treatments revealed that the hydrogen content and bonding configuration did not influence the structural properties of the crystallized films significantly. The average crystallite size in the fully crystallized films was between 100 and 150 nm. Full crystallization of 1 micrometer thick films was achieved within 20 minutes for annealing at 625°C and 650°C. During annealing at 600°C crystallization is much slower, and no crystallization is observed at 500°C. The relation between the annealing temperature and the rate with which the films are fully crystallized is of great importance to develop a solar cell technology, to limit the thermal budget and processing time.

V. Vavru

Papers

EMRS Symp B Proceedings Formation of thin-film crystalline silicon on glass observed by in- situ XRD