**7. Conclusion and perspectives**

In summary, non modified electrochemical sensor exhibited week binding and week adsorption capacity. The introduction and modification of surface functional groups was explored to improve the chemical selectivity and charge density at the active surface. The detection capacity can be improved through attachment of functional group having high affinity towards environmental pollutants. The electrochemical detection depends on the nature and structure of sensing electrode. The sensitivity and selectivity are critical core sites which enhances electrochemical analysis. CNTs enable faster transfer of electrical signal due to its high conductivity and conjugated polymers provide advanced affinity towards metal ions. Functionalized CNPs can result in highly sensitive redox sensors for a number of analytes. It can be demonstrated that the modified electrode showed excellent electro catalytic activity, increase the rate of electron transfer electron and the adsorption of the pollutants (inorganic/organic)molecules on the surface of the electrode.
