ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Calibrationless determination of electroactive species using chronoamperograms at collector segment of interdigitated microelectrode array

P. Jenčušová, P. Tomčík, D. Bustin, M. Rievaj, and Z. Dovalovská

Institute of Analytical Chemistry, Faculty of Chemical and Food Technology, Slovak University of Technology, SK-812 37 Bratislava, Slovakia

E-mail: tomcik@cvt.stuba.sk

Received: 27 July 2005  Revised: 24 February 2006  Accepted: 6 March 2006

Abstract: The possibility of calibrationless chronoamperometric determination is described using a pair of individually addressable and diffusion layers interacting segments of interdigitated microelectrode array (IDA). It utilizes dual voltammetric mode where the first segment is polarized with potential corresponding to the limiting current of determined species electrode reaction and the second segment is polarized with potential corresponding to the opposite electrode reaction limiting current. Time at which the current of the collector segment reaches one half of the steady state is hyperbolically dependent on the diffusion coefficient of analyte. The determination of diffusion coefficient allows direct calculation of bulk concentration avoiding calibration with a standard solution. The equipment for measuring of fast response of IDA arrays in dual mode has been developed using a bipotentiostat connected with A/D transducer. It allows less than 1 ms sampling period for ultrafast registration of chronoamperogram. The method was tested and validated with [Fe(CN)₆]⁴⁻, [Ru(NH₃)₆]Cl₃, and ferrocene model samples using various types of IDA arrays.

Full paper is available at www.springerlink.com.

DOI: 10.2478/s11696-006-0032-x

Chemical Papers 60 (3) 173–178 (2006)