Recently, the use of carbon nanotubes (CNTs) and fullerenes in the design of new biosensors have attracted great interest in the development of carbon nanomaterials. Due to the superior properties of CNTs and fullerenes, the use of sensor components allows the development of reliable, accurate and fast biosensors. Depending on the types of target molecules, the development and application areas of the sensors vary. This review summarizes the role of CNTs and fullerenes in the development of biosensors in different application areas. Considering the difference between other members of the nano-carbon family, we explain why CNTs are used more widely in biosensor applications and why fullerenes have high potentials in these areas of application. Moreover, we focused on investigating the function of these nano-carbons in the detection of various analytes in bio-sensing. By discussing the challenges and future expectations, we have put forward a perspective that may help synthesize advanced composites in the development of new generation designs in biosensor applications.