Enhanced Potentiometry by Metallic Nanoparticles.

Citation:

T. Noyhouzer, Valdinger, I. , and Mandler, D. 2013. “Enhanced Potentiometry By Metallic Nanoparticles.”. Anal. Chem. (Washington, Dc, U. S.)Analytical Chemistry (Washington, Dc, United States), 85, Pp. 8347 - 8353.

Abstract:

Measuring the oxidn.-redn. potential (Eh) requires an interface that is not selective toward specific species but exchanges electrons with all redox couples in the soln. Sluggish electron transfer (ET) kinetics with the species will not reflect the true Eh of the soln. Here, the authors present a novel approach by which adsorbed metal nanoparticles (NPs) were used for enhancing ET exchange rates between redox species and electrode surface and therefore affect significantly the measurement of the open circuit potential (OCP) and cyclic voltammetry (CV). The OCP and CV of various org. and inorg. species such as l-dopa, dopac, Fe(II), and iodide are measured by bare stainless steel and by stainless steel modified by either Pt or Au NPs. The authors study the effect of the surface coverage of the stainless steel surface by NPs on the electrochem. response. Also, the stainless steel electrode was modified simultaneously by Au and Pt nanoparticles. This improved concurrently the stainless steel response (CV and potentiometry) toward two different species; l-dopa, which shows fast electron transfer on Pt, and catechol, which exhibits fast electron transfer on Au. Probably this approach is a 1st step toward developing a superior electrode for measuring the true Eh of complex aquatic systems. [on SciFinder(R)]