Green synthesis of electroactive nanomaterials by using plant-derived natural products

Green synthesis of nanomaterials, with its application in electrochemical (bio)sensing, is a blooming field of research as it enables the development of sensitive electroanalytical detection devices with a minimized impact on the environment. Combining the outstanding physicochemical properties of nanomaterials with the eco-friendly and cost-effective features of green synthetic routes has proven to be greatly beneficial to the field of Electroanalytical Chemistry. Studies demonstrate the successful use of natural extracts obtained from plant tissues, such as leaves, seeds, roots, barks and fruits, to obtain nanomaterials. Bioactive compounds in plant tissues simultaneously act as reducing, capping and functionalizing agents, enabling nanoparticle synthesis procedures to be completed in a single step. The modification of electrochemical sensing platforms with biosynthesized nanostructures can considerably enhance their detection properties toward several relevant analytes, such as drugs, vitamins, metal ions and emerging pollutants. This review highlights the most recent achievements in terms of green synthesis of nanomaterials for the fabrication of eco-friendly electrochemical sensors and biosensors, with a special focus on zero-valent noble metal nanoparticles (MNPs), metal oxide nanoparticles (MONPs) and carbon-based nanomaterials.