Modification of electrodes with polymer nanocomposites: Application to the simultaneous determination of Zn(II), Cd(II), and Cu(II) in water samples

BIASI, ANTONELLA DE LAS M.; TAKARA, EDUARDO A.; SCALA-BENUZZI, MARÍA L.; VALVERDE, AGUSTINA M.; GÓMEZ, NIDIA N.; MESSINA, GERMAN A.

ANALYTICA CHIMICA ACTA

ELSEVIER SCIENCE BV

Año: 2023 vol. 1273 p. 341499 - 341505

0003-2670

Currently, there is a need for fast and sensitive analytical methods for monitoring metals in water due to theprogressive increase in the presence of metal ions in the environment. These metals reach the environmentmainly from industrial activity and heavy metals are non-biodegradable. The present work evaluates differentpolymeric nanocomposites to carry out the simultaneous electrochemical determination of Cu, Cd, and Zn inwater samples. Screen-printed carbon electrodes (SPCE) were modified with the nanocomposites, which wereobtained by a mixture of graphene, graphite oxide, and polymers, such as polyethyleneimide, gelatin, and chitosan.These polymers have amino groups in their matrix, giving the nanocomposite the ability to retain divalentcations. However, the availability of these groups plays a fundamental role in the retention of these metals. Themodified SPCEs were characterized by scanning electron microscopy, Fourier-transform infrared spectroscopy,electrochemical impedance spectroscopy, and cyclic voltammetry. The electrode that presented the best performancewas selected to determine the concentration of metal ions in water samples by square-wave anodicstripping voltammetry. The obtained detection limits were 0.23 μg L􀀀 1, 0.53 μg L􀀀 1, and 1.52 μg L􀀀 1 for Zn(II),Cd(II), and Cu(II), respectively, with a lineal range of 0.1–50 μg L􀀀 1. The obtained results made it possible toconclude that the method developed using the SPCE modified with the polymeric nanocomposite presentedadequate LODs, reasonable sensitivity, selectivity, and reproducibility. Besides, this platform is an excellent toolfor developing devices to simultaneously determine heavy metals in environmental samples.