Studies on the electrochemiluminescent behavior of luminol on indium tin oxide (ITO) glass
ABSTRACT The electrochemiluminescence (ECL) of luminol on indium tin oxide (ITO) glass was high even under a low potential around 0.4–0.5 V, which was quite different from other electrodes such as platinum. ITO nanoparticles were synthesized and used in the research on ITO glass in the ECL process. A static interaction between ITO and luminol is confirmed from UV–vis and fluorescence spectra. Then the ECL enhancement can be supposed to originate from the adsorption of luminol on ITO, which facilitated luminol’s oxidization to the excited state, giving out ECL. On the other hand, ITO can catalyze the generation of reactive oxygen species (ROSs), similar to some other nanomaterials, which also favored the ECL enhancement of luminol.
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- "In order to solve these questions, we have developed hereafter three new microsystems which derive from previous prototypes  based on ITO (Indium Tin Oxide) materials. Indeed, among the different materials of electrodes used for electrochemical detections, ITO became very popular due to its ability for optical (transparency)   and electrochemical (conductivity) recordings   . In order to preserve future optical applications, ITO has been considered here. "
ABSTRACT: The microfabrication and successful testing of a series of three ITO (Indium Tin Oxide) microsystems for amperometric detection of cells exocytosis are reported. These microdevices have been optimized in order to simultaneously (i) enhance signal-to-noise ratios, as required electrochemical monitoring, by defining appropriate electrodes geometry and size, and (ii) provide surface conditions which allow cells to be cultured over during one or two days, through apposite deposition of a collagen film. The intrinsic electrochemical quality of the microdevices as well as the effect of different collagen treatments were assessed by investigating the voltammetric responses of two classical redox systems, Ru(NH(3))(6)(3+/2+) and Fe(CN)(6)(3-/4-). This established that a moderate collagen treatment does not incur any significant alteration of voltammetric responses or degradation of the excellent signal-to-noise ratio. Among these three microdevices, the most versatile one involved a configuration in which the ITO microelectrodes were delimited by a microchannel coiled into a spiral. Though providing extremely good electrochemical responses this specific design allowed proper seeding and culture of cells permitting either single cell or cell cluster stimulation and analysis.Biophysical chemistry 03/2012; 162:14-21. DOI:10.1016/j.bpc.2011.12.002 · 2.32 Impact Factor
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ABSTRACT: A significant phenomenon is observed when indium tin oxide (ITO) glass is used as the anode in electrochemical studies. Notable luminescent signals are observed when a pulse potential is applied to an ITO electrode in alkaline solution in the absence of a luminescent reagent. This paper discusses the mechanism of this luminescence effect in detail. The investigation reveals that the reactive oxygen species (ROSs) generated during the electrolysis are O2−, OH and H2O2. It was also found that the singlet oxygen (1O2) produced subsequently acted as the indispensable light-emitting entity and the ITO was a critical intensification determinant.Electrochimica Acta 02/2012; 61:118-123. DOI:10.1016/j.electacta.2011.11.109 · 4.50 Impact Factor
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ABSTRACT: An electrochemiluminescent (ECL) biosensor based on immobilized uricase has been developed for uric acid detection with luminol as signaler. The uricase has been embedded in polypyrrole (PPy) matrix on platinum electrode during the electropolymerization of pyrrole monomer at potential of 0.80 V versus Ag/AgCl. This ECL-based biosensor responds to uric acid due to yielded hydrogen peroxide during its catalytic oxidization by uricase with potassium ferricyanide acted as an electron receptor to promote the enzymatic reaction. The so-generated hydrogen peroxide enhanced the ECL intensity of luminol. The kinetic parameters of enzymatic reaction as maximum reaction rates (Vmax) and Michaelis–Menten constants (Km) are also evaluated for 1.42 × 10−3 A s−1 and 3.4 × 10−7 M in the presence of potassium ferricyanide, which were all greatly improved. The resulting biosensor showed excellent analytical performance for determination of uric acid as more than 50 times sensitivity than a bare electrode. It gives a 75 pM of detection limit and a relative standard deviation of 4.4% for 6.25 × 10−9 M uric acid (n = 6). This ECL-based biosensor has been successfully applied for determination of uric acid in porphyra and kelp samples.Sensors and Actuators B Chemical 03/2012; 163(1):247–252. DOI:10.1016/j.snb.2012.01.047 · 4.29 Impact Factor