Use of pyrolyzed paper as disposable substrates for voltammetric determination of trace metals

Publication date: 1 April 2017
Source:Talanta, Volume 165
Author(s): Luiz André Juvêncio Silva, Weberson Pereira da Silva, Jason G. Giuliani, Sheila Cristina Canobre, Carlos D. Garcia, Rodrigo Alejandro Abarza Munoz, Eduardo Mathias Richter
The possibility of using pyrolyzed paper as disposable working electrodes for trace metals determination is reported for the first time. A small piece of pyrolyzed paper (0.7×0.7cm) was positioned at the bottom side of the electrochemical cell using a rubber O-ring, which defined the electrode area (0.48cm; 0.18cm²). A large number of electrodes can be obtained from a single piece of standard dimensions (2.5cm×7.5cm) of paper, therefore minimizing the cost per unit. The electrochemical performance of the pyrolyzed paper was demonstrated by cyclic voltammetry, electrochemical impedance spectroscopy and by the determination of Zn, Cd, and Pb by square-wave anodic stripping voltammetry. The unmodified pyrolyzed paper showed excellent performance for Pb and Cd detection (LOD =0.19 and 0.16 ppb, respectively). In the presence of Bi³⁺(in-situ film formation), the simultaneous determination of Zn, Cd and Pb was also possible (LOD=0.26, 0.25, and 0.39 ppb, respectively).

Graphical abstract

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