Green synthesis, characterization and antibacterial, antifungal, larvicidal and anti-termite activities of copper nanoparticles derived from Grewia asiatica L.

Abstract Background The current study was conducted to find out an eco-friendly and cost-efficient way to prepare copper nanoparticles (CuNPs) by utilizing Grewia asiatica L. leaf extract, which was found to be a very effective antimicrobial and larvicidal chemical. Methods Characterization of nanoparticles was also carried out by utilizing Fourier transform infrared spectroscopy (FTIR) analysis, scanning electron microscope along with X-ray diffraction analysis (XRD). The artificially prepared nanoparticles in the laboratory were approximately in the range of 2 µm in size and crystalline in nature. The CuNPs were tested for their antimicrobial activity against different types of fungi and bacteria, also some mosquito and termite. All the results and observations were tested with a one-way analysis of variance keeping the probability level at < 0.0001. Results The copper nanoparticles exhibit significant antibacterial and antifungal activities and are also found lethal for many mosquito and termite species. Antibacterial activity was checked against Escherichia coli and Bacillus subtilis , their zone of inhibition was 17 nm and 20 nm, respectively. The antifungal potential was checked against Aspergillus niger and Aspergillus oryzae and the zone of inhibition was recorded at 20 mm and 23 mm, respectively. CuNPs were also found lethal for many mosquitoes and maximum efficacy of CuNPs against Aedes aegypti larva was observed at 100 mg/ml after 24 h. Termite species such as Heterotermes indicola were exposed to CuNPs and the highest mortality rate in termites was seen at 100 ppm concentration of CuNPs. Current research provides the first investigation of CuNPs of G. asiatica as a larvicidal and as an anti-termite. G. asiatica garden-fresh leaves were collected from Railway colony Mughalpura. Conclusions This study proves that CuNPs have a toxic effect on insects and can also be utilized as a biological control of insects. By using such a scientific approach, the scientists can lower the costs of chemical usage and a biodegradable alternative could be provided.