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Ampicillin (Amp), an antibiotic, is widely used to treat bacterial infections in humans and livestock, but recently the rate of resistance has increased rapidly. The aim of this work was to enhancing the antibacterial effect of this compound against AMR Staphylococcus aureus via loading Amp into chitosan/starch nanocomposites by spray drying technique. The results showed that the different ratio of chitosan gel and starch gel used in preparing the nanocomposites can affect its properties and performance. The size distribution of the nanocomposite particles was ranging from 122.0 to 816.9 nm. The zeta potential values of the nanocomposites range from +29.47 to +93.07 mV, indicating the stability of the particles and their tendency to repel each other. Ampicillin was loaded into the chitosan/starch nanocomposites with encapsulation efficiency of 70.7–77.3 %, then their releasing and antibacterial effect against AMR S. aureus were investigated. The results indicated that antibacterial activity of chitosan/starch nanocomposites loaded ampicillin was much higher than ampicillin alone. Chitosan/starch nanocomposites loaded ampicillin at concentration 5.0 μg/mL inhibited 88.6 % growth of S. aureus to a similar extent as 7.5 μg/mL of ampicillin alone. Additionally, at same 7.5 μg/mL ampicillin concentration, the nanocomposites loaded ampicillin showed a higher inhibitory rate (93.27 %) compared to ampicillin alone (88.96 %) over a 12 h-period. Especially, the antibacterial activity of chitosan/starch nanocomposites loaded ampicillin still maintained their effectiveness over 48 h (95.43 %) while those the ampicillin decreased down to 85.76 %. This research highlights the potential of using the chitosan/starch nanocomposites as nanocarriers for ampicillin to enhance its antibacterial activity against AMR Staphylococcus aureus. This approach could be a promising strategy to combat antimicrobial resistance. [Display omitted] [ABSTRACT FROM AUTHOR]

In the present article, the disulfide tungsten/activated carbon derived from Eichhornia crassipes (WS 2 /AC) was synthesized by the hydrothermal process. The received materials were examined by X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray – mapping, and nitrogen adsorption/desorption isotherms. The morphology of WS 2 /AC was tailored to have a micro/meso/macro structure that facilized large electric conductivity and quick ion diffusion. The WS 2 /AC sample was used as an electrode modifier for developing an electrochemical sensor for salbutamol detection. WS 2 /AC exhibited excellent oxidation toward salbutamol. Through some optimized conditions, the electrochemical signal of the proposed sensor varied linearly to the salbutamol concentration ranging from 1 to 210 μM with a low LOD (detection limit) of 0.52 μM. The developed sensor showed several merits: easy producing, convenient usage, fabulous selectivity, and good repeatability as well as reproducibility. Finally, the suggested technique can be applied to determine salbutamol in people's biological fluid with satisfactory recoveries of 98.5–104.4% and without statistics different from standard HPLC. [Display omitted] • The disulfide WS 2 /AC derived from Eichhornia crassipes was synthesized. • WS 2 /AC was employed for modifying the working electrode and detecting Salbutamol. • WS 2 /AC showed superior electrochemical properties and good electrical conductivity. • WS 2 /AC exhibited excellent sensitivity for salbutamol with a LOD of 0.51 μM. [ABSTRACT FROM AUTHOR]