White light was produced exploiting an additive synthesis of red, green, and blue fluorescence through frequency upconversion in fluorolead-germanate glass codoped with Ho3+, Tm3+, Yb3+. The 475, 540, 650nm signals were, respectively, assigned to thulium (G41-H63) holmium (S25;F45)→I85 F55→I85, excited via energy tranfer from ytterbium. dopant concentrations were adjusted, yielding the emission a wide color gamut visible spectrum production white using excitation at 975nm. spectral positions...

A preconcentrating/voltammetric multiwalled carbon nanotube modified glassy electrode (MWCNT–GCE) has been developed for stripping analysis of carbendazim (Methyl Benzimidazol-2-yl Carbamate—MBC), based on dispersing MWCNT in water. The effect experimental variables, such as the dispersion and loading MWCNT, was assessed. quasi-reversible behavior MBC acetic acid/acetate buffer 0.1 mol L−1 (pH 4.7) verified its high effective pre-concentration attributed to adsorption capability enormous...

SCREEN-PRINTED ELECTRODES.A review dealing with the use of screen-printing technology to manufacture disposable electrodes is presented, covering in details virtually all publications area up early 1997 and including 206 references.The elements different strategies on constructing modified are highlighted.Commercial Home-made ink recipes discussed.Microelectrode arrays, built by combination photostructuring technologies mass production advanced sensors, also discussed.Future research trends...

The electrocatalytic activity of cobalt(II)-phthalocyanine immobilized in a carbon paste electrode for citric acid oxidation under diffusion-controlled electrochemical process was employed to develop selective flow injection amperomettric analysis method. Under optimized conditions, rapid and reliable determinations (65 samples per hour) were achieved analyses commercial fruit juices with minor pretreatment the samples. A linear response accomplished ranging from 0.25 15 mmol L(-1)...

Abstract This study investigates redox properties of fluorescein (FLSC), a fluorescent tracer with many applications in several areas, markedly biochemical research and health care diagnosis, on glassy carbon electrode (GCE) at wide interval pH by using voltammetric techniques. Three peaks were observed different potentials. The investigation revealed that FLSC is irreversibly electroxidized under diffusion‐controled pH–dependent process. oxidation process acid physiological media occurs two...

This study presents an automatic analysis system that does not require the use of standard solutions. The uses electrochemical flow cell for in line generation standards, and operates under addition technique. versatility this was demonstrated by development a one key touch fully method determination total available chlorine real samples. extremely simple, accurate inexpensive based simply on biamperometric monitoring well known redox reaction with iodide ions flow-batch system, where...

Abstract A new class of modified sol‐gel carbon composite electrodes, based on the encapsulation complexing ligands, is described. Such electrodes couple versatility and tunability processes with advantages preconcentration/voltammetric strategy. The incorporation ligand dimethylglyoxime (DMG) within carbon‐silicate ceramic network used to illustrate concept in connection voltammetric sensing trace nickel. serves as a favorable host matrix for DMG, which retains its nickel binding...

The in situ DNA-damaging capacity of berenil (1) has been investigated usingan electrochemical approach employing double stranded (ds) DNA-modified glassy carbonelectrode biosensors. Electrochemical voltammetric sensing damage caused by 1 todsDNA was monitored the appearance peaks diagnostic oxidation guanineand adenine. When incorporated directly onto biosensor surface, DNA damagecould be observed at concentrations additive as low 10 μM. In contrast, when thedsDNA-modified exposed to 1,...

The construction of a flow-through cell incorporating an array gold microelectrodes is described and its application to flow injection analysis with amperometric detection presented. Simple modification almost any conventional integrated circuit chip, used as inexpensive source pre-assembled micro-wires, leads the rapid successful preparation arrays 8–48 elements. polymeric encapsulation material from top face chip removed by abrasion until micro-wires (used interconnect silicon external...

Ricin, (Ricinus communis agglutinin, RCA) is one of the most poisonous naturally occurring substances and has great potential for bioterrorism because no antidote exists. Fast detection at low concentrations a challenge, vital to development proper countermeasures. In this study, square wave adsorptive stripping voltammetric (SWAdSV) method determining RCA using cathodically polarized boron-doped diamond (BDD) electrode presented. An irreversible electrochemical oxidation peak was identified...

Abstract Disposable complexing (preconcentrating) sensor strips for trace nickel have been fabricated by doping the screen‐printed carbon ink with ligand dimethylglyoxime (DMG). The is shown to be a useful matrix incorporating DMG, maintaining its attractive coordination chemistry following printing and firing processes. response characterized respect composition, preconcentration period potential, solution conditions other variables. A short (30 s) accumulation yields detection limit of 5...

Abstract Raltitrexede (RTX) is a folate analogue that belongs to the antimetabolites family and has antineoplastic activity correlated inhibition of thymidylate synthase (TS) enzyme. This study addresses electrochemical characterization RTX at glassy carbon electrode, on wide interval pH, using voltammetric techniques. The interaction between double helix DNA (dsDNA) in physiological medium also addressed, DNA‐electrochemical biosensor. A mechanism for oxidation proposed. irreversibly...

Abstract The electrochemical behavior of ethidium bromide (EtBr) on a glassy carbon electrode (GCE) was studied by cyclic, square wave and differential pulse voltammetry over wide pH interval. results revealed that the oxidation mechanism EtBr is an irreversible adsorption‐controlled process occurs in two consecutives steps. first step pH‐dependent at amino group C8 position with formation ortho ‐ para ‐quinone derivatives, while second pH‐independent C3 position. A method for quantitative...

Abstract This work presents a study of the electrochemical oxidation 7‐methylguanine (7‐mGua) in aqueous solution at glassy carbon electrode by cyclic voltammetry, differential pulse square wave voltammetry and impedance spectrometry. The anodic behaviour 7‐mGua was compared with electro‐oxidation guanine 7‐methylguanosine. results demonstrated that methyl ribose groups are not electroactive but strongly influence mechanism these species. occurred single pH‐dependent step, withdrawal two...