Properties Evaluation of Different Graphite Brands through the Development of Electrochemical Sensors for Phenolic Compounds Detection

Graphite is one of the most utilized materials for producing conductive inks for screen-printed electrodes (SPEs). Because of their wide range of applications, several brands are available in the market. Consequently, it is possible to find particles with different properties. In this context, these differences can generate variations in the device performance. Based on this, the present work compares paper analytical devices (PADs), which were prepared with three different graphite brands and photographic paper, to evaluate how these possible distinctions can affect the devices' performance. CA detection was carried out with square wave voltammetry, where the devices produced with Fisher Chemical and Sigma-Aldrich graphite stood out for their high stability and current magnitude. Under the optimized parameters, analytical curves were constructed for each PAD, resulting in 5.0 × 10^-6 to 1.0 × 10^-4 mol L^-1 and 5.0 × 10^-7 to 1.0 × 10^-4 mol L^-1 for that manufactured with Fisher Chemical and Sigma-Aldrich graphite, respectively. In addition, the limits of detection were 1.39 μmol L^-1 for the one produced with Fisher Chemical graphite and 0.288 μmol L^-1 for the one produced with Sigma-Aldrich graphite.