Bionanotechnology: The formation of copper nanoparticles assisted by biological agents and their applications as antimicrobial and antiviral agents

Abstract

The aim of researchers to create a matter that has a few preferences in diverse areas of pharmaceutical, agricultural, and natural remediation has fueled the creation and advancement of nanoscience and nanotechnology. Nanoparticles have been a primary focus of development in materials science throughout the last few decades. The study of copper nanoparticles (both in metallic copper and copper oxide) is economically attractive because copper is significantly more affordable than silver and gold. Moreover, the utilization of copper nanoparticles can substitute silver and gold nanoparticles in a few areas, specifically antimicrobial activity, antiviral activity, and others. Recently, copper nanoparticles research has been focused on the alternative fabrication process that concerns sustainability and environmentally friendly processes. Due to the several limitations of conventional methods, the novelty, and eco-friendly concern, studies have been shifted toward biological synthesis and its possibility to produce copper nanoparticles. This paper focuses on the alternative methods (biological synthesis) of copper nanoparticles, including the factors that affect the nanoparticles’ formation, such as temperature, precursor concentration, pH, reaction time, and the probable reduction mechanism. Also, as climate change triggers new infectious diseases caused by viruses and bacteria, this paper reviewed the copper nanoparticles’ ability as antimicrobial (antifungal and antibacterial) and antiviral agents. As precursors, the optimal temperatures are 80 °C (for CuSO4·5H2O and CuCl2.2H2O), 70 °C (for Cu(CH3COO)2.H2O), and 60 °C (for Cu(NO3)2.3H2O). The optimum precursor concentration is 2 mM for CuSO4·5H2O The optimum pH ranges from 4 to 10. Each reductant and precursor has its own reaction time for forming copper nanoparticles, ranging from 1 to 120 min.