Artículos de revistas
Graphite Screen-printed Electrodes Applied For The Accurate And Reagentless Sensing Of Ph
Registro en:
Graphite Screen-printed Electrodes Applied For The Accurate And Reagentless Sensing Of Ph. Amer Chemical Soc, v. 87, p. 11666-11672 DEC-2015.
0003-2700
WOS:000365931100012
10.1021/acs.analchem.5b01236
Autor
Galdino
Flavia E.; Smith
Jamie P.; Kwamou
Sophie I.; Kampouris
Dimitrios K.; Iniesta
Jesus; Smith
Graham C.; Bonacin
Juliano A.; Banks
Craig E.
Institución
Resumen
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) A reagentless pH sensor based upon disposable and economical graphite screen-printed electrodes (GSPEs) is demonstrated for the first time. The voltammetric pH sensor utilizes GSPEs which are chemically pretreated to form surface immobilized oxygenated species that, when their redox behavior is monitored, give a Nernstian response over a large pH range (1-13). An excellent experimental correlation is observed between the voltammetric potential and pH over the entire pH range of 1-13 providing a simple approach with which to monitor solution pH. Such a linear response over this dynamic pH range is not usually expected but rather deviation from linearity is encountered at alkaline pH values; absence of this has previously been attributed to a change in the pKa value of surface immobilized groups from that of solution phase species. This non-deviation, which is observed here in the case of our facile produced reagentless pH sensor and also reported in the literature for pH sensitive compounds immobilized upon carbon electrodes/surfaces, where a linear response is observed over the entire pH range, is explained alternatively for the first time. The performance of the GSPE pH sensor is also directly compared with a glass pH probe and applied to the measurement of pH in real unbuffered samples where an excellent correlation between the two protocols is observed validating the proposed GSPE pH sensor. 87 23
11666 11672 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) British Council [172726574] Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)