Nanoscale Au particles are received with significant interest in the recent years owing to their unique properties, which originate from the quantum scale dimension. Although colloidal Au has been known since ancient times for the decoration of glasses and for its curative powers, the technological importance has been understood only in the last two decades. The fascinating optical and electronic properties of the Au nanoparticles made them an excellent candidate in the development of nanoscale devices. Significant amount of research has been devoted to explore the technological application of these tiny particles. Various biosensing devices, catalytic interfaces and bioanalytical methodologies based on Au nanoparticles have been developed in the last two decades for different applications. Au nanoparticles are considered to be the key building blocks in the emerging nanoscale energy and sensing devices of 21(st) century. In this review, we highlight some of the recent patents and related literature on the bioanalytical applications of Au nanoparticles. A brief outline on the synthesis of Au nanoparticles of various size and shape and a detailed account of their potential utilization in the development of optical and electrochemical sensors/biosensors and analytical methods for drug delivery are discussed.