Abstract
Metal contaminated wastewater represents a major environmental problem of global concern. Traditional detection techniques cannot perform rapid and cost-effective on site-measurements. Recently, carbon dots (CDs) have been applied to detect metal ions in water samples; their efficient performance is attributed to the unique properties, e.g., fluorescence, water solubility, and photostability. CDs prepared from biomass and waste materials present additional advantages, e.g., lower costs and abundant and sustainable sources. This review presents biomass/waste-derived CDs to detect metal ions. Finally, possible research directions to achieve sustainability in metal sensing are suggested according to the current challenges presented in biomass/wastederived CDs.