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Dopamine (DA) is a crucial neurotransmitter in the central nervous system (CNS) of human and multicellular animal brains. In this paper, we report for the first time the synthesis of carbon black (C)/phosphotungstic acid (PWA) composites by doping PWA on carbon black nanoparticles by impregnation method. The synthesized materials were characterized using high‐resolution scanning electron microscopy (SEM), X‐ray diffraction spectroscopy (XRD) and Fourier transform infrared spectroscopy (FT‐IR). Glassy carbon electrodes (GCE) modified by C/PWA composites were used to detect dopamine. The electrochemical redox behavior of DA was studied with cyclic voltammetry (CV). Under optimized conditions, DA was detected by differential pulse voltammetry (DPV) and the calibration plot showed linearity (R2=0.9988) over the range of DA concentrations of 10 μM‐600 μM with a detection limit of 0.1 μM. The sensor's capability to detect DA in commercial DA injections in real time has been successfully demonstrated. [ABSTRACT FROM AUTHOR]

Bisphenol A (BPA) is an environmental endocrine disrupting chemical, which can lead to various adverse health effects. Aiming to develop effective tools for the detection of BPA, this work reports a low cost and stable film based on casein (CAS) and Carbon Black (CB). The proposed material (CAS‐CB) showed structures of CAS surrounded by CB agglomerates observed by Scanning Electron Microscopy while Fourier Transform Infrared Spectroscopy analysis illustrated characteristic bands of casein. Cyclic Voltammetry (CV) and linear sweep voltammetry (LSV) were used to investigate the electrochemical behavior of BPA using the CAS‐CB. Under optimal conditions, LSV detection presented a limit of detection of 0.25 μmol L−1 in a linear range from 0.49 to 24 μmol L−1. Additionally, the working electrode (GC) modified by the proposed film (CAS‐CB) was applied for BPA sensing in environmental and milk samples. The results showed recoveries between 95.4 to 114 % attesting the efficiency of this new material, which has simplicity in the preparation, high conductivity, and adsorption capability. [ABSTRACT FROM AUTHOR]