Gold nanocrystals and nanorods functionalized with protein and polymeric ligands for environmental, energy storage, and diagnostic applications: A review

This comprehensive review explores the utilization of gold nanocrystals (Au NCs) and gold nanorods (Au NRs) functionalized with protein and polymeric ligands for various environmental applications. These applications include drug delivery, diagnostics, and environmental monitoring. This review also explores the biogenic synthesis of Au nanocrystals and nanostars, characterization techniques, and their analytical applications in environmental contexts. Moreover, integrating Au nanocrystals with ligand-receptor chemistry enables rapid and efficient cell detection and separation. Notably, fluorescent polymer-Au nanocrystals exhibit a unique characteristic that renders them highly valuable for energy storage devices such as batteries and supercapacitors. Incorporating these NCs into electrode materials can enhance charge storage capacity, electrochemical performance, and cycling stability. Furthermore, they can enhance light absorption, charge separation, and transfer process in solar cells. The fluorescence properties of these NCs also enable them to serve as specific probes for identifying contaminants, including heavy metals, organic compounds, and environmental toxins. The fluorescence can be tuned to interact with particular analytes, enabling accurate detection and measurement. Additionally, these NCs can be functionalized to enhance pollutant removal, thereby increasing their adsorption capacity and catalytic activity. Collectively, fluorescent polymers incorporating Au nanocrystals hold immense potential in energy storage systems and environmental applications. They offer improved performance, sensitivity, and efficiency. Consequently, researchers actively explore ways to enhance and expand their utilization to address energy and environmental challenges.