Synthesis of copper nanoparticles by a sonication-mediated method using Malpighia glabra fruit extract and their applications

Abstract

This study introduces an environmentally friendly technique for copper nanoparticle synthesis utilizing Malpighia glabra fruit extract under the sonication treatment. The synthesis process and phenol red removal were optimized by a central composite full and response surface design. Highly pure and spherical-shaped copper nanoparticles with an average size of 22.5 nm were formed using 7.4 mL of Malpighia glabra fruit extract and 21.9 mM (AcO)₂Cu. Additionally, the extract-mediated nanoparticles opposed the negative charges with a zeta potential of −11.8 mV and high stability of 30 days storage time. The sonication-assisted nanoparticles exhibited the highest inhibition against Gram-positive bacteria (Bacillus subtilis and Staphylococcus aureus), MCF7 human breast cancer cells, and Fusarium solani with 50% inhibition concentrations reaching 12, 0.82, and 80 ppm, respectively. Additionally, the green-synthesized nanomaterials functioned as an effective catalyst to remove phenol red. A conversion of 97% after a 540 seconds reaction was determined on 10 ppm phenol red with the presence of 21.5 ppm copper nanoparticles and 51.8 mM NaBH₄. This research highlights the potential of Malpighia glabra fruit extract in the sustainable production of copper nanoparticles, with promising applications in biomedicine, agriculture, and environmental remediation.