Table 3.

Mainadvantages and drawbacks of the major techniques reviewed in this manuscript.

Techniques	Advantages	Drawbacks
Metallic or carbon electrodes	Sub-ppb detection Easily miniaturisable On-field detection	Lack of specificity Lack of reproducibility Formation of intermetallic compounds Formation of biofilms and fouling
Chemically modified electrodes with CPs	Sub-ppb detection Specificity Anti-fouling	Sensibility Stability
Electrodes modified with biomolecules	Specificity	Costs Long-term stability Not yet available for on-field detection