Nanocomposites and nanomaterials

Carbon nanotubes as a base material for working electrodes increasing the sensitivity of determinations in striping voltammetry

M. Grabarczyk1*, M. Adamczyk1, E. Wlazlowska1

1 Department of Analytical Chemistry, Institute of Chemical Sciences, Faculty of Chemistry, Maria Curie-Skłodowska University, Maria Curie-Skłodowska Sq. 3, 20-031 Lublin, Poland
*E-mail: malgorzata.grabarczyk@mail.umcs.pl 

Stripping voltammetry (SV) is a powerful technique for determination of low levels of metal ions. The key element in voltammetric procedures is the selection of the working electrode. The first procedures were developed using hanging mercury drop electrodes, however their major drawback was high toxicity. In recent years, the literature has described many different working electrodes which use the formation of metallic films, most often on a glassy carbon substrate [1,2]. In our research, we used nanotubes to modify the working electrode thanks to which the sensitivity of the determinations was increased compared to the procedures based on classic glassy carbon electrodes. The carbon nanotubes modified electrode was obtained by mixing carbon nanotubes and epoxy resin. The resulting paste was put under pressure in glass capillary of diameter 2 mm. Such composition turns out to be a very good basis for metal film formation. The use of this electrode has the additional advantage: the deoxygenating of the sample before measurement is unnecessary. It also simplifies the apparatus necessary to perform metal ions determination in field conditions. To confirm the applicability of nanotubes to modify the working electrode the stripping voltammetric determination of selected metal ions in nanoconcentrations in natural water samples was performed.

References 
[1] Grabarczyk M., Adamczyk M. New Strategies for the Simple and Sensitive Voltammetric Direct Quantification of Se(IV) in Environmental Waters Employing Bismuth Film Modified Glassy Carbon Electrode and Amberlite Resin//Molecules -2021, -26, -P. 4130    
[2] Adamczyk M., Grabarczyk M. Simple and Fast Simultaneously Determination of In(III) and Ti(IV) Using Lead Modified Glassy Carbon Electrode by Stripping Voltammetry//J. Electrochem. Soc. -2020, -167, -P. 126515