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This study investigates potentiodynamic synthesis of polyaniline (PANI) using pencil graphite electrodes (PGEs), aiming to elucidate deposition mechanisms under simple experimental conditions. By exploring PANI electrosynthesis through electrochemical, spectroscopic, and computational approaches, valuable insights into the physicochemical aspects of aniline polymerization are gained. The proposed synthetic method was challenged for the development of a new molecularly imprinted polymer for chloramphenicol on the surface of PGEs to obtain an innovative impedimetric sensor. The sensing platform shows a linear response in the target concentration range between 0.1 and 17.5 nM, in aqueous solutions, with a limit of detection of 0.03 nM and a limit of quantification of 0.09 nM. The results obtained suggest that the synthesis method proposed provide a way to obtain stable and electroactive polyaniline film with huge potential application. [ABSTRACT FROM AUTHOR]

Herein the synergistic properties of electrochemically reduced graphene oxide–antimony nanoparticles (ERGO-SbNPs) were leveraged for the ultrasensitive determination of bisphenol A (BPA) in water samples using disposable pencil graphite rods. A novel pencil-graphite multi-electrode array was utilized as the coating tool resulting in the production of highly reproducible and disposable single-use ERGO-SbNP-coated pencil graphite rods. This coating method effectively mitigated the fouling caused by BPA by-products during oxidation. The analytical determination of BPA oxidation on the single-use ERGO-SbNP-coated pencil graphite rods demonstrated an impressive 0.0,125 µM detection limit, surpassing the USEPA drinking water standard of 0.087 µM. Furthermore, the developed electrochemical sensor exhibited exceptional reproducibility for BPA in tap water samples from Western Cape, South Africa with few interferences. The study's findings not only highlight the sensor's superior performance but also present a promising alternative to existing anti-fouling measures. [ABSTRACT FROM AUTHOR]

In this study, the electrochemical properties of etofenamate, an active ingredient belonging to the non-steroidal anti-inflammatory drug group, were investigated using cyclic voltammetry (CV) and square wave voltammetry (SW) techniques on a disposable pencil graphite electrode (PGE). With the CV technique, reversible voltammetric waves of around +0.470 V and irreversible voltammetric waves of around +1.02 V were produced on the PGE. An environmentally friendly, selective and highly sensitive SW voltammetric method was developed using disposable PGE. This voltammetric method gave very good analytical working range on PGE in PBS (pH = 3.0) medium at concentrations ranging from 0.017 μM to 0.306 μM. The LOD value of this analytical method in PBS (pH = 3.0) medium was calculated as 0.0011 μM (0.406 μg L−1). The developed voltammetric method was successfully applied to urine and drug samples. The results of the voltammetric method were compared with the results of the spectrophotometric method. The results were found to be compatible with each other. [Display omitted] • Pencil graphite electrode was employed for the first time for determination of Etofenamate. • Benefits of method: rapidity, simplicity, sensitivity and repeatability. • The procedure was successfully applied to determination of Etofenamate urine and drug samples. [ABSTRACT FROM AUTHOR]

• Evanescent fiber optic sensing and DFT approach in graphite pencil powder introduced. • Black graphite pencil powder exhibited better sensitivity for ethanol at room temperature. • DFT analysis supported the experimental results with better adsorption energy and distance. This study investigated the ethanol-sensing properties of pencil graphite using a fiber optic gas sensor. The results were further confirmed using density functional theory (DFT). The sensor showed good sensitivity (18 counts/100 ppm) and response time (70 sec). The electronic analysis of pure and ethanol-adsorbed graphite powders was also conducted using their band structures, Density of States (DOS), and projected Density of States (PDOS). For ethanol-adsorbed graphite, it was shown that there were significant alterations in band structure and density of states, providing insights for gas sensing applications. [ABSTRACT FROM AUTHOR]