Gold on the horizon: unveiling the chemistry, applications and future prospects of 2D monolayers of gold nanoparticles (Au-NPs)

Noble 2D monolayers of gold nanoparticles (Au-NPs) have garnered significant attention due to their unique physicochemical properties, which are instrumental in various technological applications. This review delves into the intricate physical chemistry underlying the formation of Au-NP monolayers, highlighting key interactions such as electrostatic forces, van der Waals attractions, and ligand-mediated stabilization. The discussion extends to the size- and shape-dependent assembly processes of these NP monolayers, elucidating how nanoparticle dimensions and morphologies influence monolayer formation and stability. Moreover, the review explores the diverse interfaces-solid, liquid, and air-where Au-NP monolayers are employed, each presenting distinct advantages and challenges. In the realm of applications, Au-NP monolayers have shown remarkable promises. In memory devices, their ability to facilitate high-density data storage through enhanced electron transport mechanisms is examined. Biosensing applications benefit from the monolayers' exceptional sensitivity and specificity, which are crucial for detecting biomolecular interactions. Furthermore, the role of Au-NP monolayers in electrocatalysis is explored, with a focus on their catalytic efficiency and stability in various electrochemical reactions. Despite their potential, the deployment of Au-NP monolayers faces several challenges. The review addresses current limitations such as scalability, reproducibility, and long-term stability, proposing potential strategies to overcome these hurdles. Future prospects are also discussed, including the development of multifunctional monolayers and integration with other nanomaterials to enhance performance across different applications. In conclusion, while significant strides have been made in understanding and utilizing 2D Au-NP monolayers, ongoing research is imperative to fully exploit their capabilities. Addressing existing challenges through innovative approaches will pave the way for their widespread adoption in advanced technological applications.