Synthesis and antibacterial activity of metallic copper-chitosan nanomaterial using environmentally friendly Cleistocalyx operculatus leaf extract as a reducing agent

The copper-chitosan nanomaterial (CuNPs-CTS) was effectively produced through a chemical reduction process employing Cleistocalyx operculatus leaf extract (COLE) as a reduction agent and chitosan as a stabilization agent. Both COLE and chitosan were derived from natural sources and are environmentally friendly. Various techniques including XRD, SEM, TEM, and DLS were used to characterize the samples. The findings revealed the exclusive presence of CuNPs metal when COLE was used as the reducing agent, while the presence of both metallic Cu and Cu2O was the result of using NaBH4. The CuNPs-CTS material synthesized with COLE displayed CuNPs particles with diameters varying from 10 to 30 nm. CuNPs-CTS materials were tested for their antibacterial activity against Escherichia coli and Staphylococcus aureus bacteria. CuNPs-CTS materials effectively inhibited the growth of these bacteria, significantly expanding the bacterial inhibition zone compared to the control sample (distilled water). The CuNPs-CTS material using COLE exhibited a bacterial inhibition zone diameter of around 20 and 18 mm against S. aureus and E. coli, respectively. This surpassed the antibacterial performance of the CuNPs-CTS material employing NaBH4 against S. aureus (18 mm). image