Theory of analytical spectroelectrochemistry

Xie, Yuanwu; Dong, Shaojun

doi:10.1016/0022-0728(90)87133-5

Cited by 4 publications

(4 citation statements)

References 6 publications

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“…Spectroelectrochemical techniques have demonstrated the capability of detecting various analytes in aqueous solutions. Their potential utility was examined early on by the use of a grazing angle optical configuration. , In one study, the absorbance of electrochemically generated metal−hydroxo complexes was monitored and used to quantitate the free metal ions of interest . The same optical configuration also was used to demonstrate the detection of electroactive organic compounds .…”

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confidence: 99%

Simultaneous Detection of Two Analytes Using a Spectroelectrochemical Sensor

2010

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Spectroelectrochemical sensors developed in our group achieve three modes of selectivity by combining electrochemistry, spectroscopy, and a chemically selective membrane in a single device. Analyte detection is based upon a change in the optical response due to the conversion of the analyte between two oxidation states that results from the cycling or stepping of the applied potential. We have demonstrated a novel approach to simultaneously detect two metals by combining optical stripping voltammetry for one metal (Pb(2+)) and the in situ ligand complexation in a film for the other metal (Fe(2+)). Using an indium tin oxide (ITO) sensor platform with a 50 nm Nafion film to preconcentrate the analytes, equimolar mixtures of Pb(2+) and Fe(2+) in 0.1 M sodium acetate buffer (pH 5) were detected. Pb(2+) was detected by optical stripping voltammetry, in which lead was deposited as metal on the ITO and detected by the optical change as it was removed by stripping. The ferrous ion was detected by the in situ ligand complexation method in which Fe(2+) was complexed with 2,2'-bipyridyl in the Nafion in the film to form an intense red complex that was detected by absorbance at 520 nm. Detection limits of 300 and 400 nM were obtained for Pb(2+) and Fe(2+), respectively. The presence of the film had no effect on the optical signal that results from the deposition and stripping of the Pb(2+). In addition, competition between the Pb(2+) and Fe(2+) for sites in the film and for the organic ligand was investigated.

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confidence: 99%

Simultaneous Detection of Two Analytes Using a Spectroelectrochemical Sensor

2010

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“…Xie and Dong reported the derivation of theoretical relations and experimental verification of analytical SEC determination for analytes involved in simple, reversible electrode processes, [8] electrocatalytic electrode reactions, [9] and electrodeposition processes (anodic stripping). Yao et al have reported a general theoretical and experimental treatment of potentialstep chronoabsorptometric determination of reversible analytes, [10] and have P. A.…”

Section: Introductionmentioning

confidence: 99%

Fiber Optic Spectroelectrochemical Sensing forin situDetermination of Metal Ions

Flowers¹,

Arnett²

2007

Spectroscopy Letters

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In situ chemical sensing techniques are increasingly used for a variety of applications, including industrial process control, on-site environmental assessment, and detection of explosives and chemical and biological weapons. A common category of sensors for such purposes entails the use of optical fibers for making spectral measurements of target compounds or species derived from these compounds via physical, chemical, enzymatic, or immunologic reactions. A less common but potentially advantageous approach involves the electrochemical conversion of the analyte subsequent to its spectroscopic detection. These spectroelectrochemical schemes represent versatile, essentially reagent-free analyses that could provide superior alternatives to existing methods. Reported here is a summary of progress made by the authors' group toward the development of fiber optic spectroelectrochemical sensors for in situ measurements. The aqueous copper (II)/copper (0) couple was chosen as a model system to investigate the merit of an analytical scheme involving (i) cathodic preconcentration of Cu 2þ as Cu 0 followed by (ii) anodic stripping of Cu 0 to Cu 2þ , (iii) complexation of Cu 2þ by an appropriate ligand, and finally (iv) absorbance determination of the copper-ligand complex or fluorescence determination of the unbound ligand. Results are encouraging and indicate the need for further refinement of the sensor's design and the experimental protocol in order to improve the method's sensitivity.

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“…Some of the spectroelectrochemical studies have been performed with optically transparent electrodes (OTEs), such as metal minigrids with mercury thin films plated on them [16,17] or indium tinoxide (ITO) electrodes where the chemical compounds are directly deposited on them [18][19][20]. In contrast, other spectroelectrochemical stripping experiments have been carried out with solid electrodes such as glassy carbon electrodes [21][22][23]. Depending on the electrode, different light beam configurations can be used, such as normal incidence to an OTE [16,17], attenuated total internal reflectance [18][19][20], or parallel incidence to the working electrode surface [21][22][23].…”

Section: Introductionmentioning

confidence: 99%

“…Depending on the electrode, different light beam configurations can be used, such as normal incidence to an OTE [16,17], attenuated total internal reflectance [18][19][20], or parallel incidence to the working electrode surface [21][22][23]. Until now, stripping spectroelectrochemistry has been applied to determination of toxic heavy metals, including their mixtures, namely copper [21,22], lead and cadmium [18], mercury and lead [19], or cadmium and copper [20]. However, none of the existing spectroelectrochemical stripping methods has exploited the great potential of bismuth film electrodes.…”

Section: Introductionmentioning

confidence: 99%