Indian knowledge system plant based carbon dots: synthesis and optical sensing applications for environmental remediation

Abstract

One of the major problems in recent decades has been the absorption of harmful chemicals and toxins into the human body, either directly or indirectly. The excessive usage of heavy metals, like Cr(VI), Pb(II), As(II), Cd(II), and organic contaminants such as pesticides, dyes, disinfectants, and food additives, and their untreated discharge by the industries, has had a profound effect on the environmental water systems as well as on the food chain. This ultimately impacts the human race. Carbon dots (CDs), a relatively new, cost-effective and sustainable nanomaterial, has recently gained attention as an alternative solution to address this issue, due to numerous benefits, such as additional value to waste, utilizing pollution-free resources and green processing procedures. Substantial type of precursors for green CDs have employed various plants from Indian knowledge system and have been used to detect metal ions and other organic contaminants in water. Some examples include tulsi leaves for detection of Cr(VI), mango peels for detection of the pesticide, mesotrione, Aegle marmelos (bael patra fruit) for detection of allura red, Fe(III), and Cu(II). The CDs synthesised using turmeric powder have been explored for degradation of acid azo dyes. It is well known that the ancient Indian knowledge system has consistently emphasized the role of nature in benefiting the human race. Vast Indian plant wealth is now finding alternate, sustainable ways to contribute towards the conservation of the environment. Thus, the Indian knowledge system may continue to act as a tool for protecting the environment and in turn the human race, using green nanotechnology.