Gold nanoparticles are widely used in medical applications, particularly in diagnostics and treatment. They serve as effective contrast agents in imaging techniques like CT scans and electron microscopy, enhancing the visibility of tissues and cells. In cancer therapy, gold nanoparticles are utilized in photothermal treatment, where they absorb light and convert it into heat to destroy cancer cells. They are also employed in drug delivery systems, enabling targeted and controlled release of medications to specific areas in the body. In the field of electronics, gold nanoparticles are integral in the development of conductive inks and coatings, which are essential for printing flexible circuits and sensors. Their unique optical properties make them valuable in the creation of advanced optical devices and sensors, including those used for detecting environmental pollutants or biological molecules. Additionally, gold nanoparticles play a significant role in catalysis, where they facilitate various chemical reactions with high efficiency. They are particularly useful in environmental applications, such as the degradation of harmful pollutants in water and air. Their versatility and unique properties make them a crucial component in advancing technology and improving health and environmental outcomes.