ABSTRACT
Nanoparticles (NPs) are tiny materials that range from 1 to 100 nm and can be classified into many groups depending on their sizes, shapes, and properties. Plant phytochemicals such as flavonoids, alkaloids, polyphenols, terpenoids, and other phytochemicals are very important as stabilizing, reducing and capping agents in biological methods. Flavonoids are a type of natural product with a complex structure that is present in the plant kingdom. They are a type of secondary plant metabolite. Flavones, flavanonols, flavanols, flavanones, isoflavones, neoflavanoids, and chalcones are some of the subgroups of flavonoids. The polyhydroxy group in flavonoids is important for free radical scavenging and antioxidant characteristics and its role in metal ion reduction via NP synthesis. The NPs synthesized from flavonoids have shown potential antimicrobial, anti-inflammatory, antitumour, antioxidant, antibiofilm, catalytic and cytotoxic activity. They are also used for drug delivery, real sample detection, heavy metal removal, and IR-absorbing optical coatings. Quercetin and rutin are used for the preparation of spherical silver NPs used as antibacterial activities. Tricetin kaempferol, formononetin, kaempferol, and genistein flavonoids are also used for the preparation of spherical gold NPs for antibacterial, anticancer, and antiangiogenic activities. TEM, SEM, FTIR, UV-Vis, XRD, DLS, TGA, EDX, and zeta potential have all been used to characterize the NPs that were produced. This chapter aims to provide the most up-to-date information on flavonoid-based fabrication of NPs, their characterization, and application. To use synthesized NPs more effectively in drug delivery and human welfare, more extensive research in the field of NPs synthesis using flavonoids is required.
