ABSTRACT
A sensitive biological system and a detector system with appropriate transducers for obtaining the output signals make up a biosensor. These devices have a wide range of uses, including disease screening, the detection of environmental pollutants, agriculture, and routine medical examinations. The product's selectivity, sensitivity, stability, and lower production costs will all be critical factors in its widespread commercialisation. Recently, scientists have tackled the issue of developing a nano biosensor with a high degree of sensitivity and selectivity for the recognition of biomarkers of immune responses and cancer. The fact that electrochemical nano biosensors may successfully be employed for detecting medications in addition to pathogen biomarkers has significantly altered the covid picture in our favour. During the worldwide epidemic, a number of cutting-edge SARS - CoV-2 biosensors with portable, smartphone-connected instant detection devices were helpful. This article provides a concise summary of the underlying working principle, generations of developments and numerous detection methods employed by electrochemical biosensors.The difficulties, knowledge gaps, and possible solutions in the field of electrochemical biosensors are all discussed in the context of this categorisation.This novel overview also sheds light on the different kinds of electrochemical biosensors and the tasks they perform, as well as recent developments in the "smart biosensor” industry with potential future directions and challenges for this growing subject.