Green synthesis of copper nanoparticles from an extract of Jatropha curcas leaves: characterization, optical properties, CT-DNA binding and photocatalytic activity

Abstract

The green synthesis of copper nanoparticles (CuNPs) using a leaf extract from Jatropha curcas (JC) has been documented in our present research work. The existence of flavonoids, tannins, glycosides, and alkaloids was confirmed by the phytochemical analysis of the plant extract and these chemicals can be used as reducing, stabilizing and capping agents. After six months, the JC-CuNPs were found to be stable without any evidence of agglomeration. The JC-CuNPs were characterised by XRD, FT-IR, SEM, TEM and UV-vis spectrophotometry. The average particle and crystal sizes of the JC-CuNPs were found to be 10 ± 1 and 12 ± 1 nm, respectively. The SPR peaks were found at 266 and 337 nm, measured using electronic spectroscopy, and the calculated optical band gap was found to be 3.6 eV at 337 nm, indicating the semiconductor behaviour of the JC-CuNPs. JC-CuNPs have potential photocatalytic activity against methylene blue (MB) compared with other dyes in the presence of sunlight and the rate constant (k) value is 2.30 × 10⁻⁴ s⁻¹. The JC-CuNPs also have a binding property with CT-DNA through an intercalation mode and the binding constant (K_b) is 1.024 × 10² M⁻¹.