Biosynthesis of Nanoparticles Using Plant Extracts and Essential Oils

Abstract

Plant extracts and essential oils have a wide variety of molecules with potential application in different fields such as medicine, the food industry, and cosmetics. Furthermore, these plant derivatives are widely interested in human and animal health, including potent antitumor, antifungal, anti-inflammatory, and bactericidal activity. Given this diversity, different methodologies were needed to optimize the extraction, purification, and characterization of each class of biomolecules. In addition, these plant products can still be used in the synthesis of nanomaterials to reduce the undesirable effects of conventional synthesis routes based on hazardous/toxic chemical reagents and associate the properties of nanomaterials with those present in extracts and essential oils. Vegetable oils and extracts are chemically complex, and although they are already used in the synthesis of nanomaterials, limited studies have examined which molecules are effectively acting in the synthesis and stabilization of these nanostructures. Similarly, few studies have investigated whether the molecules coating the nanomaterials derived from these extracts and essential oils would bring benefits or somehow reduce their potential activity. This synergistic effect presents a promising field to be further explored. Thus, in this review article, we conducted a comprehensive review addressing the main groups of molecules present in plant extracts and essential oils, their extraction capacity, and available methodologies for their characterization. Moreover, we highlighted the potential of these plant products in the synthesis of different metallic nanomaterials and their antimicrobial capacity. Furthermore, we correlated the extract's role in antimicrobial activity, considering the potential synergy between molecules from the plant product and the different metallic forms associated with nanomaterials.

Keywords: antibacterial activity; antioxidant activity; carotenoids; essential oils; green synthesis; nanoparticles; plant extracts; polyphenols.

Figure 1

Various compounds can be extracted from different plant sources and applied to different areas, including the biosynthesis of nanomaterials. Different plant parts, such as flowers, fruits, and leaves, can be used to prepare extracts or oils. Various techniques can be employed, such as maceration and extraction using a rotary evaporator, affecting which composts will be efficiently extracted from the plant material. The plant extracts or essential oils produced can be used to synthesize nanomaterials through different protocols that may or may not involve heating.

Figure 2

Biological activities of plant extracts.

Figure 3

The green synthesis of nanomaterials from plant extracts with different biological properties.