RESUMO
Ciprofloxacin (CIP), a broad-spectrum fluoroquinolone antibiotic, is commonly used in aquaculture to prevent and treat bacterial infections in aquatic animals. For this reason, aquatic environments contain CIP and its derivatives, which lead to the development of drug-resistant bacteria. In the present study, copper nanoparticles were prepared using Garcinia mangostana extract (GME-CuNPs) as a reducing agent and evaluated for their CIP removal efficiency (CRE). The results demonstrate that within 20 min, GME-CuNPs at 25 mM possess a CRE of 92.02 ± 0.09% from CIP-containing aqueous media with pH 6-7. The CRE is influenced by both monovalent and divalent salts. A high salt concentration significantly reduces the CRE. Contaminants in fish wastewater can reduce the CRE, but phenolics, flavonoids, tannins, and ammonia do not affect the CRE. Our results reveal that the CRE is controlled by electrostatic attraction between the negatively charged GME-CuNPs and the cationic species of CIP. The CRE is reduced by wastewater with a pH higher than 8.0, in which the CIP molecules have a negative charge, resulting in a repulsive force due to the negative charge of GME-CuNPs. In fish wastewater with a pH lower than 7.0, GME-CuNPs show the potential to achieve a CRE above 80%. Therefore, pH adjustment to a range of 6-7 in fish wastewater before treatment is deemed imperative. It is concluded that the newly developed GME-CuNPs possess excellent activity in CIP elimination from actual fish wastewater samples. Our findings suggest that GME-CuNPs can be a promising tool to effectively eliminate antibiotics from the environment.
RESUMO
Ciprofloxacin (CIP) is frequently detected in the environment and causes the emergence of drug-resistant bacteria. High levels of CIP in the environment are also harmful to humans and animals. Therefore, effective elimination of CIP is required. In this study, plant-based copper nanoparticles (CuNPs) have been fabricated for the purpose of eliminating CIP. Aqueous extracts of 6 plants were compared for their phytochemicals and reducing activity. Among all the extracts, Garcinia mangostana extract (GM) was the most potent with the highest total phenolic compounds, flavonoids, tannins, terpenoids, and reducing activity. CuNPs synthesized using GM (GM-CuNPs) were characterized using UV-VIS spectroscopy and dynamic light scattering. The results showed that the maximum absorption of GM-CuNPs was at 340 nm. The average size of GM-CuNPs is in the nanoscale range of 159.2 ± 61 nm, with a narrow size distribution and a negative zeta potential of - 4.13 ± 6.97 mV. The stability of GM-CuNPs is not solely due to their zeta potential but also phytochemicals in the extract. GM-CuNPs at 25 mM showed the highest efficiency of 95% in removing CIP from aqueous medium pH 6-7 at 25-35°C within 20 min. The results indicated that the electrostatic attraction between the negative charge of GM-CuNPs and the positive charge of CIP controlled the drug adsorption on the nanoparticles. In conclusion, the developed GM-CuNPs have excellent CIP removal efficiency. These synthesized GM-CuNPs are expected to be environmentally friendly for the removal of antibiotics and other drugs.
