Carbon-fiber microsensor for in vivo monitoring of trace zinc(II) based on electrochemical stripping analysis
2001; Elsevier BV; Volume: 3; Issue: 7 Linguagem: Inglês
10.1016/s1388-2481(01)00175-8
ISSN1873-1902
AutoresJoseph Wang, Samo B. Hočevar, Randhir P. Deo, Božidar Ogorevc,
Tópico(s)Electrochemical sensors and biosensors
ResumoThe optimization and characterization of a microsensor for trace zinc based on stripping voltammetry at a single carbon-fiber microelectrode are reported. Despite the absence of a mercury coverage, the carbon-fiber stripping sensor displays a significant hydrogen overvoltage in the physiological pH and a well-defined zinc stripping peak (at ca. −1.17 V). 5 s deposition periods allow convenient quantitation of zinc over the 100–1000 ng/ml (ppb) range. Detection limits of 0.8 ng/ml (1.2×10−8 M) and 20 ng/ml (3.0×10−7 M) zinc were estimated in connection to 60 and 1 s deposition, respectively. The response is reversible with the stripping/measurement step completely removing the accumulated zinc. Measurement frequencies as high as 30 runs per min can thus be realized (in connection to 1 s deposition and measurement steps). The influence of relevant variables of the deposition and stripping steps is examined. The attractive behavior of the stripping-voltammetric microsensor offers great promise for in vivo monitoring of trace levels of zinc.
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