Zero-, one- and two-dimensional carbon nanomaterials as low-cost catalysts in optical and electrochemical sensing of biomolecules and environmental pollutants

An arousing attention on carbon-based nanomaterials in the last two decades research is mainly owing to their exceptional opto-electronic properties besides their superior chemical, thermal and mechanical properties. Because of the peculiar properties of the 0-D carbon dots (CDs) and graphene quantum dots (GQDs), 1-D carbon nanotubes (CNTs) and 2-D graphene and graphitic carbon nitride (g-CN), they have been highly utilized in opto-electrochemical and biosensors for the sensitive detection of complex analytes. Carbon nanomaterials based optical and electrochemical sensors showed excellent sensitivity and selectivity and better linear range and with detection limit for the sensing of wide range of analytes of chemicals, pollutants and biomolecules. This review article envisions a wide-range study on the advances in optical and electrochemical sensors for the detection of biomolecules and environmental pollutants based on variety of carbon nanomaterials carried out by Late. Prof. S. Abraham John, who dedicated his career to the opto-electrochemical sensors through the innovative use of metal and carbon nanomaterials. Important goals achieved using graphene, CNTs, CDs, GQDs and g-CN are described. Besides, highlighting their characteristic features, synthetic approaches and promising exploitations in the recent development of opto-electrochemical receptors for the sensing of biomolecules, drugs and environmental pollutants. The fabrication of the nanocomposites of carbon and metal nanoparticles and their applications are also discussed. Finally, highlighting the recent concepts and the future developments in this field are presented.