This review explores the synthesis, properties, and multidisciplinary applications of gold nanoparticles (GNPs), with a focus on their role as biosensors. GNPs possess unique physicochemical attributes, including size-dependent optical properties, biocompatibility, and ease of functionalization, making them promising for biosensing platforms. The review covers various synthesis techniques, highlighting their advantages and disadvantages. It delves into the properties that underpin their success in biosensing, such as localized surface plasmon resonance (LSPR) and enhanced surface area. The discussion also includes functionalization strategies that enable specific binding to biomolecules, enhancing sensitivity and selectivity. The review surveys diverse applications of GNPs in biosensing, including diagnostics, environmental monitoring, and drug delivery, emphasizing their versatility and potential in addressing complex challenges in healthcare and environmental science. The need for further exploration and research in nanobiotechnology, particularly in the synthesis, properties, and biosensing applications of GNPs, is highlighted. With their exceptional attributes and versatile functionalities, GNPs present a promising avenue for advancing biosensing capabilities and broader scientific innovation.This review explores the synthesis, properties, and multidisciplinary applications of gold nanoparticles (GNPs), with a focus on their role as biosensors. GNPs possess unique physicochemical attributes, including size-dependent optical properties, biocompatibility, and ease of functionalization, making them promising for biosensing platforms. The review covers various synthesis techniques, highlighting their advantages and disadvantages. It delves into the properties that underpin their success in biosensing, such as localized surface plasmon resonance (LSPR) and enhanced surface area. The discussion also includes functionalization strategies that enable specific binding to biomolecules, enhancing sensitivity and selectivity. The review surveys diverse applications of GNPs in biosensing, including diagnostics, environmental monitoring, and drug delivery, emphasizing their versatility and potential in addressing complex challenges in healthcare and environmental science. The need for further exploration and research in nanobiotechnology, particularly in the synthesis, properties, and biosensing applications of GNPs, is highlighted. With their exceptional attributes and versatile functionalities, GNPs present a promising avenue for advancing biosensing capabilities and broader scientific innovation.