The health challenges associated with pathogens and ectoparasites highlight the need for effective control approaches. Metal nanoparticles have been proposed as highly effective tools towards combatting different microbial organisms and parasites. The present work reports the antimicrobial and larvicidal potential of biosynthesized Ag/Ag₂O nanoparticles using aqueous leaf extract of Eupatorium odoratum (EO). The constituents of the leaf extract act as both reducing and stabilizing agents. The UV-VIS spectra of the nanoparticles showed surface plasmon resonance. The particle size and shape of the nanoparticles was analysed by transmission electron microscopy (TEM). The larvicidal study was carried out using third and fourth instar Culex quinquefasciatus larvae. The mosquito larvae were exposed to varying concentrations of plant extract (EO) and the synthesized nanoparticles, and their percentage of mortality was accounted for at different time intervals of 12 h and 24 h periods of exposure. The nanoparticles were more lethal against third and fourth instars of Culex quinquefasciatus larvae at the 24 h period of exposure with lower lethal concentration values (LC50 = 95.9 ppm; LC90 = 337.5 ppm) and (LC50 = 166.4 ppm; LC90 = 438.7 ppm) compared to the plant extract (LC50 = 396.8 ppm; LC90 = 716.8 ppm and LC50 = 448.3 ppm; LC90 = 803.9 ppm, respectively). The antimicrobial properties of the nanoparticles were established against different clinically-isolated microbial strains and compared to that of the plant extract (EO) and standard antimicrobial drugs. The nanoparticles were generally more active than the plant extract against the selected microbial organisms. The Gram-negative bacterial strains Escheerichua coli and Salmonella typhi were more susceptible towards the nanoparticles compared to the Gram-positive strains and the fungal organism.

In this paper, a commercial polymeric resin precursor (polystyrene sulphonate beads) was used as a source of carbon spheres. The resin was pyrolyzed at different temperatures (700, 800, and 900 °C) and the resulting carbons were analyzed by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). From the result of EIS, carbon spheres obtained at 700 °C (CS−700) have the least ohmnic resistance and highest capacitance. In furtherance, the resin was chemically activated with iron (III) chloride FeCl₃·6H₂O at different concentration (0.1 M, 0.3 M, and 0.5 M) and pyrolyzed at 700 °C to obtain activated carbon sphere namely (ACS 700−0.1, ACS 700−0.3, and ACS 700−0.5) in which the last digit of the samples denotes the concentration of FeCl₃. Scanning electron microscope (SEM) showed that the carbon is of spherical shape; X-ray diffraction (XRD), energy dispersive spectroscopy (EDS), and X-ray photon electron spectroscopy (XPS) revealed successful introduction of Fe on the surface of the carbon. Out of all the activated carbon spheres, ACS 700−0.1 exhibited highest double layer capacitance of 9 µF cm⁻² and lowest charge transfer resistance of 3.33 KΩ·cm². This method shows that carbon spheres obtained from a polymeric source can be easily improved by simple resin modification and the carbon could be a potential candidate for an electrical double layer capacitor.