Síntesis y caracterización de nanopartículas de óxido de aluminio a partir de Cyphomandra betaceae para evaluar su actividad bactericida en el río Chibunga

Abstract

The indiscriminate use of antibiotics has led to the development of resistance mechanisms in bacteria. Water from contaminated rivers plays a crucial role in the propagation of this phenomenon. Therefore, the objective of the present investigation was to carry out the green synthesis and characterization of aluminum oxide nanoparticles as a possible bactericidal agent for water treatment at the confluence point of the Chibunga and Chambo rivers. The Al2O3 nanoparticles were obtained using an aqueous extract of tomato tree Cyphomandra Betacea as a reducing agent and aluminum sulfate as a precursor salt. The characterization was performed by Uv-vis spectroscopy, infrared spectroscopy (IR), and scanning electron microscopy (SEM). Meanwhile, bacterial inhibition tests evaluated bactericidal activity by performing sowings in nutrient agar at one-hour intervals of exposure of the water samples to the nanoparticles. Statistical analysis, using Pearson's correlation, revealed a high negative correlation between the number of colonies and the exposure time, since a considerable reduction in the bacterial load was observed from the first hour of contact with the nanoparticles. In addition, optimal conditions for nanoparticle formation were determined at 0.025 M concentration of the precursor salt and 80°C temperature. According to the scanning electron microscopy analysis, the resulting Al2O3NPs showed an average size between 65 and 71 nm with an oval shape, characteristics that favored their bactericidal effectiveness. For this reason, it is concluded that Al2O3NPs present a remarkable bactericidal activity against drug-resistant colonies in river water samples. This stands out as an effective alternative for water decontamination.