פרסומים

The present invention relates to electrochem. initiated bioadhesive compns. comprising biocompatible polymers contg. derivs. of diazonium, arylsulfonium, or diaryliodonium in general, and to their use in tissue fixation, in particular. [on SciFinder(R)]

Sol-gel/carbon nanotube (CNT) nano-composite films were electrochem. deposited by applying a neg. potential to a conducting substrate, i.e. indium tin oxide (ITO) and an Ag grid printed on polyethylene terephthalate (PET). The deposition is driven by the local pH rise on the cathode that catalyzes the formation of sol-gel films. The latter serve as a binder and trap for CNTs. The deposition can be well manipulated by the deposition potential and time, and the film can be selectively electrodeposited on the conductive parts of Ag grids printed on PET from an optimized dispersion. The thickness, transmittance, morphol. and hydrophilicity of the films are characterized by profilometry, spectrophotometry, SEM (SEM) and water contact angle, resp. It is further revealed that the electrodeposited sol-gel/CNT composite films have non-linear optical properties and exhibit pronounced antireflective performance (specular reflection < 0.5%) over a visible to long-wave IR range, allowing their potential application as optical materials. [on SciFinder(R)]

The electrochemical detection of mercury in aqueous solutions was studied at glassy carbon (GC) and indium-tin oxide (ITO) electrodes modified by gold nanoparticles (Au NPs). Two methods of modification were used: electrochemical reduction of HAuCl4 and electrostatic adsorption of Au NPs stabilized by citrate. We found that the Au NPs modified surfaces yielded higher sensitivity and sharper and more reproducible stripping peaks of Hg as compared with the bare electrodes. The effect of the modification by Au NPs on the stripping potential was examined. Interestingly, the stripping of Hg on GC and ITO modified by Au NPs occurred at the same potential as on bare GC and ITO, respectively. Only the full coverage of ITO by either electrochemically deposited Au for a long time or by vapor deposition, shifted the stripping potential more positive by ca. 0.4 V to that observed on a bare Au electrode. These and further experiments led us to conclude that the Au NPs served as nucleation sites for the deposition of Hg, whereas the GC or ITO are superior for the stripping of mercury. Hence, a combination of well-defined Au NPs on ITO or GC were found ideal for the electrochemical detection of Hg. Indeed, we achieved a remarkable detection limit of 1 μm·L(-1) of Hg using an ITO surface modified by electrostatically adsorbed Au NPs.[on SciFinder (R)]

The electrochem. detection of Hg in aq. solns. was studied at glassy C (GC) and In-Sn oxide (ITO) electrodes modified by Au nanoparticles (Au NPs). Two methods of modification were used: electrochem. redn. of HAuCl4 and electrostatic adsorption of Au NPs stabilized by citrate. We found that the Au NPs modified surfaces yielded higher sensitivity and sharper and more reproducible stripping peaks of Hg as compared with the bare electrodes. The effect of the modification by Au NPs on the stripping potential was examd. Interestingly, the stripping of Hg on GC and ITO modified by Au NPs occurred at the same potential as on bare GC and ITO, resp. Only the full coverage of ITO by either electrochem. deposited Au for a long time or by vapor deposition, shifted the stripping potential more pos. by \~0.4 V to that obsd. on a bare Au electrode. These and further expts. led us to conclude that the Au NPs served as nucleation sites for the deposition of Hg, whereas the GC or ITO are superior for the stripping of Hg. Hence, a combination of well-defined Au NPs on ITO or GC were found ideal for the electrochem. detection of Hg. We achieved a remarkable detection limit of 1 μm/L of Hg using an ITO surface modified by electrostatically adsorbed Au NPs. [on SciFinder(R)]

The units of concn. of mercury noted as "μm L-1" should read as "ng L-1.". [on SciFinder(R)]

In this work we report the sensitive electroanalytical detection of uranium(VI) in aqueous solutions. Uranium commonly exists in aqueous solutions in the form of its oxo ion, uranyl (U(VI)O2(2+)). The detection of uranyl has been accomplished by us through its deposition upon reduction by two electrons to the insoluble UO2 using a bare disk gold macroelectrode and anodic stripping voltammetry (ASV). This gave an unsatisfactory detection limit of ca. 1 × 10(-5) M uranyl. Moreover, the evolution of hydrogen bubbles blocked the electrode surface as a result of water reduction at negative deposition potential (-0.7 V vs Ag/AgCl). The application of a 25 μm diameter Au microwire electrode on which UO2 precipitated at negative potential (-1.2 V) improved substantially the detection limit. Further improvement was accomplished by vibrating the microwire working electrode, which increased the amounts of UO2 deposition due to decreasing the diffusion layer. The effect of the vibrating amplitude and frequency on the electroanalytical response was studied and optimized. Eventually, a detection limit of ca. 1 × 10(-9) M uranyl was achieved using a 5 min deposition time, -1.2 V deposition potential, and vibrating the electrode at frequency of 250 Hz and amplitude of 6 V.[on SciFinder (R)]

The authors report the sensitive electroanal. detection of uranium(VI) in aq. solns. Uranium commonly exists in aq. solns. as its oxo ion, uranyl (UVIO22+). The detection of uranyl was accomplished by the authors through its deposition upon redn. by two electrons to the insol. UO2 using a bare disk gold macroelectrode and anodic stripping voltammetry (ASV). This gave an unsatisfactory detection limit of \~1 × 10-5 M uranyl. Also, the evolution of hydrogen bubbles blocked the electrode surface as a result of water redn. at neg. deposition potential (-0.7 V vs. Ag/AgCl). The application of a 25 μm diam. Au microwire electrode on which UO2 pptd. at neg. potential (-1.2 V) improved substantially the detection limit. Further improvement was accomplished by vibrating the microwire working electrode, which increased the amts. of UO2 deposition due to decreasing the diffusion layer. The effect of the vibrating amplitude and frequency on the electroanal. response was studied and optimized. Eventually, a detection limit of \~1 × 10-9 M uranyl was achieved using a 5 min deposition time, -1.2 V deposition potential, and vibrating the electrode at frequency of 250 Hz and amplitude of 6 V. [on SciFinder(R)]

An electrochemical insulin-delivery system based on reduced graphene oxide impregnated with insulin is described. Upon application of a potential pulse of -0.8 V for 30 min, up to 70 ± 4% of human insulin was released into a physiological medium while preserving its biological activity.[on SciFinder (R)]

An electrochem. insulin-delivery system based on reduced graphene oxide impregnated with insulin is described. Upon application of a potential pulse of -0.8 V for 30 min, up to 70 ± 4% of human insulin was released into a physiol. medium while preserving its biol. activity. [on SciFinder(R)]

A method of manufg. an electrochromic device is provided. The method includes providing a patterned arrangement of an elec. conductive material; and applying one or more layers of an electrochromic material to the patterned arrangement, wherein at least a portion of the electrochromic material is in elec. contact with the elec. conductive material. An electrochromic device and an electrochromic ink compn. are also provided. [on SciFinder(R)]

A method of manufg. an electrochromic device is provided. The method includes providing a patterned arrangement of an elec. conductive material; and applying one or more layers of an electrochromic material to the patterned arrangement, wherein at least a portion of the electrochromic material is in elec. contact with the elec. conductive material. An electrochromic device and an electrochromic ink compn. are also provided. [on SciFinder(R)]