This work presents synthesis, and characterization of a novel [diresorcinate‐1,10‐phenanthrolinecobalt(II)] (DHRPCo) complex, and potentiodynamic fabrication of poly(DHRPCo)/GCE for SWV determination of procaine penicillin G (ProPenG) in various pharmaceutical and biological samples. While UV‐Vis and FT‐IR results demonstrated stepwise synthesis of DHRPCo, the CV and EIS results evidenced modification of the surface of GCE by an electroactive polymer film that improved electrode surface area. In contrast to the peak of ProPenG at the unmodified electrode, an irreversible oxidative peak at poly(DHRPCo)/GCE with lower potential and six folds of current enhancement observed, that confirmed electrocatalytic effect of the polymer, SWV response of poly(DHRPCo)/GCE showed linear dependence on concentration of ProPenG in the range 0.1–200 μM, with LoD of 4.9 nM. Spike recovery results in various pharmaceutical and biological samples in the range 98.03–106.50 %, interference recovery in the presence of selected potential interferents at their various levels with associated errors under 3.39 %, and stability of the modifier with analysis time validated the method for determination of ProPenG. Poly(DHRPCo)/GCE was applied for determination of ProPenG in three brands of injection pharmaceutical formulation, human urine, human blood serum, and cow's milk samples. While no ProPenG was detected in the human urine, serum, and cow's milk samples, detected ProPenG in the injection powder samples was within 96.1–101.3 % of company label. The developed method showed superior performance over recently reported methods making it an excellent candidate for determination of ProPenG in real samples.

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In this work, two complexes of ruthenium(III) ([Ru(phen)2Cl2]Cl·2H2O and [Ru(phen)2(G)Cl]2Cl·H2O) were synthesized from 1,10-phenanthroline alone as well as from both 1,10-phenanthroline and guanide. The synthesis was checked using halide test, conductance measurement, and spectroscopic (ICP-OES, FTIR, and UV/Vis) analysis. Their in vitro antibacterial activities were also investigated on two Gram-positive (Staphylococcus aureus (S. aureus) and methicillin resistant Staphylococcus aureus (MRSA)) and two Gram-negative (Escherichia coli (E. coli) and Klebsiella pneumoniae (K. pneumoniae)) bacteria. These complexes showed wide-range better activities than the commercially available controls (Chloramphenicol and Ciprofloxacin) against even the most drug resistant K. pneumoniae. [Ru(phen)2(G)Cl]2Cl·H2O inhibited S. aureus, MRSA, E. coli, and K. pneumoniae by 17.5%, 27.4%, 16%, and 52%, respectively, better than Chloramphenicol. It also inhibited these pathogens by 5.9%, 5.1%, 2.3%, and 17.2%, respectively, better than Ciprofloxacin. Similarly, [Ru(Phen)2(Cl)2]Cl·2H2O inhibited these pathogens by 11%, 8.7%, 0.1%, and 31.2%, respectively, better than Chloramphenicol. Therefore, after in vivo cytotoxicity investigations, these compounds can be considered as potential antibiotic drugs.

This study covers the development of a fast, selective, sensitive, and stable method for the simultaneous determination of cephalosporins (cephalexin (CLN) and cefadroxil (CFL)) in biological fluids and tablet samples using potentiodynamic fabrication of a poly(resorcinol)-modified glassy carbon electrode (poly(reso)/GCE). The results of cyclic voltammetry and electrochemical impedance spectroscopy supported the modification of the GCE by a polymer layer that raised the electrode surface area and conductivity. At the poly(reso)/GCE, an irreversible oxidative peak with four- and fivefold current enhancement for CLN and CFL, respectively, at a substantially lower potential demonstrated the catalytic action of the modifier. Under optimized solution and parameters, the peak current response at the poly(reso)/GCE revealed a linear dependence on the concentration of CLN and CFL within the range 0.1–300 and 0.5–300 μM, respectively, with a limit of detection (LoD) of 3.12 and 8.7 nM, respectively. The levels of CLN in four selected tablet brands and CFL in two tablet brands were in the vicinity of 91.00–103.65% and 97.7–98.83%, respectively, of their nominal values. The recovery results for CLN in pharmaceutical samples were in the range of 99.00–100.67% and for CFL 97.9–99.75% and for blood serum and urine samples 99.55–100.55% and 99.33–100.34% for CLN and 97.13–100.60% and 96.73–102.50% for CFL, respectively. Interference recovery results with errors less than 4.81%, lower LoD, wider dynamic range, excellent recovery results, and good stability of the modifier compared to those for the previously reported methods validated the use of the poly(reso)/GCE for determining CLN and CFL simultaneously in various real samples.

Among the various agricultural outputs, coffee is one of the most popularly consumed beverage worldwide. Consequently, it has taken a significant market share in the World market and more than 121 countries are exporting coffee to different countries (http://www.ecea.org.et/uk/). Analysis of caffeine, trigonelline, and chlorogenic acid levels in green coffee is vital for the coffee industry because they have a paramount effect on the overall quality of the brewed coffee and coffee products (de Maria et al., 1995). When coffee is roasted, most of the aroma and flavor are originated from trigonelline and chlorogenic acids (Heo et al., 2020;de Maria et al., 1995). Even though caffeine is unaffected during the roasting process, it is directly linked with its pharmacological effects (de Maria et al., 1995;. Hence the quality of green coffee beans is directly related to the composition of these constitu-