Improper disposal of pharmaceutical drugs, including antibiotics, can affect the ecological system and generate serious health problems for living organisms. In this work, we have developed an electrochemical sensor based on a strontium manganese oxide/functionalized hexagonal boron nitride (SrMnO₃/f-BN) electrocatalyst for the detection of the antibiotic drug furaltadone (FLD). Various analytical techniques were used to characterize the physicochemical properties of the as-prepared SrMnO₃/f-BN composite. The as-fabricated SrMnO₃/f-BN composite electrode showed excellent sensing activity towards FLD, with a wide linear range (0.01–152.11 µM) and low detection limit (2.0 nM). The sensor exhibited good selectivity towards FLD for detection in the presence of various interfering species (nitro compounds, metal ions, and biological compounds). Interestingly, real-time analysis using the proposed SrMnO₃/f-BN composite was able to determine the FLD content in human urine and wastewater samples with good recovery. Hence, the as-developed SrMnO₃/f-BN modified sensor could be viable in practical applications to target the antibiotic drug FLD in both human fluids and environmental samples.

A glassy carbon electrode (GCE) coated with delafossite CuCrO₂ loading on the nitrogen-doped reduced graphene oxide (N-rGO) and multiwalled carbon nanotubes (MWCNT) composite (N-rGO-MWCNT/CuCrO₂) was applied to the hydrogen evolution reaction and Bisphenol-A (BPA) detection. First, the N-rGO-MWCNT composite was prepared by in situ chemical reduction with caffeic acid as a reducing agent. Then, CuCrO₂ was accumulated on the N-rGO-MWCNT surface to form N-rGO-MWCNT/CuCrO₂ composite. The morphology structure of the N-rGO-MWCNT/ CuCrO₂ composite was analyzed by different characterization techniques. Besides, the GCE/N-rGO-MWCNT/CuCrO₂ composite electrode was investigated for hydrogen evolution reaction (HER), which shows an excellent electrocatalytic activity with a low over-potential, increasing reduction current, and a small Tafel slope of 62 mV·dec⁻¹ at 10 mA·cm⁻² with long-term stability. Moreover, the electrochemical determination of BPA was in the range of 0.1-110 µM, and low detection limit of 0.033 µM (S/N = 3) with a higher sensitivity of 1.3726 µA µM⁻¹ cm⁻². Furthermore, the prepared GCE/N-rGO-MWCNT/CuCrO₂ electrode shows effective detection of BPA in food samples with acceptable recoveries. Hence, the finding of GCE/N-rGO-MWCNT/CuCrO₂ can be observed as an impressive catalyst to the electrocatalytic activity of HER and BPA oxidation.

In this study, we synthesized heterostructured zinc stannate/tin oxide microparticles (ZTO/TO MPs) by a simple coprecipitation method and used them as an effective electrode material for the electrochemical detection of the antibacterial drug secnidazole (SCZ). The as-prepared ZTO/TO MPs were characterized by XRD, Raman, FE-SEM, HR-TEM, EDX, and XPS analyses. The physiochemical studies clearly proved that the fabricated ZTO/TO MPs were formed in a heterostructure phase without other impurities. A glassy carbon electrode modified with the synthesized ZTO/TO MPs showed an excellent and improved electrocatalytic activity in the electrochemical reduction of SCZ. Using differential pulse voltammetry (DPV), an impressive linear calibration range, extending from 0.01 to 193 μM, was observed, coupled with a detection limit of 0.0054 μM and a sensitivity of 0.055 μA/μM. In addition, the ZTO/TO MPs/GCE showed very good selectivity for the detection of SCZ in the presence of a number of biological, inorganic, and structurally related compounds. Finally, the ZTO/TO MPs/GCE was investigated for the analysis of SCZ in human blood serum samples. A very good recovery was obtained when spiking the blood serum with SCZ, highlighting the good applicability of the ZTO/TO MPs/GCE for the electrochemical analysis of SCZ in complex biological samples.