Biosynthesis and characterization of ZnO, MnO, and FeO nanoparticles: Exploring the role of tomato pomace as reducing agents

Nanotechnology is revolutionizing multiple industries by providing novel solutions that leverage the unique properties of materials at the nanoscale. As this field continues to evolve, it will likely become an integral part of technological advancement in the 21st century. This research aims to use tomato pomace from the industry to formulate bio-synthesized nanoparticles. The purpose of utilizing tomato pomace was that the extract is rich in bioactive compounds such as phenols, flavonoids, antioxidants, and tannins that serve as natural stabilizing and reducing agents, enabling the synthesis of nanoparticles with controlled morphology and size. The physiochemical analysis showed total phenolic content (TPC): 102.74±1.14 mg GAE/g, total flavonoid content (TFC): 111.06±1.27 mg QE/g), total tannin content (TTC): 43.02±0.644 mg GAE/g, and DPPH radical scavenging activity (RSA) 68.32±1.91% found in tomato pomace (TP). The bio-synthesis method is used to formulate FeO, ZnO, and MnO nanoparticles where tomato pomace extract is used as a reducing and capping agent. The formulated nanoparticles were confirmed by certain analyses such as FESEM, XRD, FTIR, UV spectrum, and visual inspection. The XRD confirms the crystalline nature, and the pattern demonstrates nine distinguish peaks for ZnO, one for MnO, and five for FeO. Further, FESEM confirmed that the size of formulated nanoparticles ZnO, MnO and FeO ranges below 100nm. The bio-synthesis process for preparing nanoparticles will be an alternative to traditional chemical methods, which are more environmentally friendly and cost-effective. Certain studies have been done on nanoparticles and more are yet to be done to valorise the waste.