It is block D element and the nanoparticles of the gold are very soft in nature. The versatile surface of the gold nanoparticles allows them to be coated with molecules, polymers, and biological recognition molecules. However, these particles are spherical in their morphology and brown in appearance. These particles have a wide variety of applications. Gold nanoparticles are anti-fungal and anti-biotic agent when they are added in the plastics, coatings, and textiles. Similarly, these particles are also used in catalyst applications. Apart from this, these particles have efficient use in photodynamic therapy. The modern technology of food detection in which these nanoparticles along with colorimetric sensor can identify either the food is suitable or not for its consumption. However, the scattered colors of these Gold nanoparticles allow them to be used in biological imaging applications. Similarly, they are also used in detecting the biomarkers in diagnosing cancer, infectious agents and heart diseases.