Recent Advances and Synthetic Approaches of AuNRs for Sensing Applications Based on Different Aspect Ratios

Gold nanorods (AuNRs), 1D rod-shaped nanomaterials, hold a crucial role in sensing applications due to their distinct physicochemical properties, such as high surface area, efficient mass transfer, good biocompatibility, and anisotropic optical and electronic responses. This review outlines the most recent advancements in AuNRs research, offering a comprehensive summary of synthetic strategies. Subsequently, the potential of AuNRs in sensor applications is discussed, and for the first time, an innovative analysis of their application in the sensor field based on the aspect ratio of AuNRs is proposed. These sensing systems are utilized for detecting heavy metal ions, inorganic anions, small biomolecules, protein tumor markers, enzymes, and nucleic acids. Finally, the future research directions and challenges of AuNRs are addressed.