Ruthenium nanoparticles doped on electrochemical activated screen-printed electrode for simultaneous determination of dopamine and paracetamol in pharmaceutical and human serum samples

A simple and highly selective electrochemical method using the commercially available screen-printed electrode electrochemically activated (ASPE) by cyclic voltammetry in 1.0 M H2SO4 and modified with ruthenium nanoparticles (RuNPs) was developed for the simultaneous determination of dopamine (DA) and paracetamol (PA). Changes in electrochemical behavior before and after the electrochemical activation of ASPE were studied by CV and EIS. The results have shown that the electrochemical activation of ASPE can improves the electrical conductivity, large surface area, and thus resulting in the formation of conducting RuNPs/ASPE nanocomposite. The morphologies and interface properties of the obtained RuNPs/ASPE nanocomposite were examined by FE–SEM, TEM, EDX, XRD, and AFM. Moreover, the electrochemical performances of the nanocomposite were investigated by CV, EIS and SWV methods. After optimization, the results show that CV, SWV, and EIS can effectively detect DA and PA using the fabricated sensor. For individual detection, SWV and EIS proved to be better techniques, particularly SWV, which exhibited the highest sensitivity (1.93 and 1.06 μA mM−1 cm−2) and the lowest detection limits (0.11 μM for DA and 0.17 μM for PA). However, for simultaneous detection, CV is more advantageous, providing the widest linear ranges (1.0–300 μM for DA and 1.0–400 μM for PA). Furthermore, the newly RuNPs/ASPE sensor showed excellent repeatability, reproducibility, stability, and selectivity. This sensor was successfully applied to measure PA and DA in both human blood and pharmaceutical formulations with satisfactory recovery

Screen-printed electrodes decorated with low content Pt–Ni microstructures for sensitive detection of Zn(II), ascorbic acid and paracetamol in pharmaceutical products and human blood samples

In this study, we report for the first time, a method for simultaneous detection of paracetamol (PA) and its toxic impurities, 4-aminophenol (4-AP), as well as commonly co-formulated drugs, ascorbic acid and zinc (AA and Zn(II)), using screen-printed electrodes (SPEs) as a sensing platform. To improve the electrochemical performance of the SPEs, these are decorated with platinum and nickel microstructures (Pt–Ni), using a simple electrodeposition technique. The structures and morphologies of the synthesized Pt–Ni/SPE electrode were confirmed by FE–SEM, TEM, EDX, XRD and AFM measurements. Furthermore, electrochemical characterization of the as-prepared sensor was investigated using cyclic voltammetry and electrochemical impedance spectroscopy methods. Under optimum conditions, the content of 4-AP, PA, AA and Zn(II) was quantified using cyclic voltammetry, differential pulse voltammetry and square-wave voltammetry techniques. The designed sensor exploits a dual effect, leveraging the efficiency of Pt for Zn(II) detection and Pt–Ni for the detection of 4-AP, AA, and PA. On one hand the as-prepared Pt–Ni/SPE sensor exhibits a linear response towards 4-AP and PA, ranging from 0.5 to 200 μM for both, with detection limits of 0.33 µM and 0.23 µM (S/N = 3) for 4-AP and PA, respectively. On the other hand, it demonstrates a linear response towards PA, AA, and Zn(II), ranging from 0.01 to 0.8 μM for Zn(II), 10 to 1800 μM for AA, and 0.5 to 200 μM for PA, with detection limits of 0.004 µM, 9.0 µM, and 0.15 µM for Zn(II), AA, and PA, respectively. Crucially, the as-fabricated sensor, with its remarkable reproducibility, recovery, long-term stability, and anti-interference capabilities, effectively quantified 4-AP, PA, Zn(II) and AA in both pharmaceutical formulations and human plasma samples

Simultaneous determination of 4-aminophenol and paracetamol based on CS-Ni nanocomposite-modified screen-printed disposable electrodes

In the present work, chitosan-coated nickel nanoparticles (CS-Ni) were successfully prepared onto screen-printed electrode (SPE) by electrodeposition method with the assistance of an anionic surfactant of sodium dodecyl sulfate (SDS) for the individual and simultaneous sensing of 4-aminophenol (4-AP) and paracetamol (PA). The as-prepared sensor was characterized via scanning electron microscopy, X-ray diffraction, and fourier transform infrared techniques. The electrochemical catalytic behaviors of the 4-AP and PA on the fabricated NiNPs-SDS/CS/SPE electrode were explored using cyclic voltammetry (CV), differential pulse voltammetry (DPV), and electrochemical impedance spectroscopy (EIS). The NiNPS-SDS/CS modified screen-printed electrode demonstrated excellent electrocatalytic activity for 4-AP and PA, indicating that nickel microstructures have a high specific surface area, excellent electrical conductivity, and high electrocatalytic activity. The results indicate that CV and DPV could be easily applied to determine 4-AP and PA using the fabricated sensor under optimized conditions. However, CV is preferred for both analysts’ sensing, with the largest linear range from 1 to 500 μM for 4-AP (R2 = 0.999) and 1 μM to 2 mM (R2 = 0.997) for PA, respectively. In terms of sensitivity and detection limit, DPVs response appeared to be a better technique choice, as it revealed the highest sensitivity values of 0.959 µA µM−1 cm−2 for 4-AP and 1.163 µA µM−1 cm−2 for PA, with the lowest detection limits of 0.06 and 0.04 μM for 4-AP and PA (S/N = 3), respectively. With a high recovery rate, good selectivity, excellent reproducibility, and strong anti-interference ability, the modified sensor was successfully applied to the simultaneous detection of 4-AP and PA in pharmaceutical tablets. It is expected to be widely used in actual sample detection