Nanobiomaterials-enabled sensors for heavy metal detection and remediation in wastewater systems: advances in synthesis, characterization, and environmental applications

Currently, heavy metal pollution in water and wastewater has garnered significant attention due to its adverse effects on environmental and human health. Conventional detection and remediation techniques often fall short because of their complexity, cost, and limited efficiency. In response, nanobiomaterials (NBMs)-based sensors have emerged as promising alternatives, offering high sensitivity, specificity, and rapid detection of trace levels of heavy metals such as lead, cadmium, and mercury. These contaminants typically originate from industrial discharge and agricultural runoff. NBMs, which merge the advantages of nanotechnology and biomaterials, exhibit high surface area-to-volume ratios and tailored surface functionalities, making them effective adsorbents for heavy metal ions even at low concentrations. Among various NBMs, graphene-based adsorbents have shown notable efficiency and sustainability in treating industrial effluents. Similarly, nanocellulose-graphene oxide composites have proven capable of removing diverse pollutants such as heavy metals, pesticides, oils, and dyes, while also functioning as sensors for real-time monitoring. The research underscores the significance, limitations, and potential applications of these materials in advanced wastewater treatment. Future studies should prioritize optimizing the synthesis, surface modification, and regeneration of NBMs to ensure their scalability and long-term applicability in large-scale treatment systems. Overall, NBMs represent a transformative approach in addressing the persistent challenges of heavy metal contamination in aquatic environments.