The increasing growth of nano techniques with better appreciative in electrochemical methods make nano electrode array sensing in bioanalysis has gained attention in the recent past. Biosensors being employed to monitor pollution, bio-recognition events and interactions. The scientific society witnessed their applications in food-quality control, health care, environmental monitoring military, industrial process control, and microbiology. Biosensing strategy evolved greatly from in vitro studies with bio-sensing ability of organic beings to the sophisticated nanofabrication enabled biosensors. The coupling of nanotechnology with bio-sensing led to the improvement of novel sensors with sensing mechanisms and increased the sensitivity and efficiency than existing biosensors. The array and nanoelectrode ensembles (NEA and NEE) have been played as a electroanalytical tool due to unique behavior such as improved signal/noise ratio, enhanced mass transportation, and suitability for extreme miniaturization and have been exploited to improve electrochemical biosensors in which NEA/NEE surfaces being functionalized with biorecognition layers. This chapter discussed the recent progress with innovative techniques for nanofabrication methods, functioning of NEA/NEE and their unique biosensing applications.