Click chemistry in the electrochemical systems: Toward the architecture of electrochemical (bio)sensors

Click chemistry is considered one of the most powerful tools used to design a variety of compounds or complexes including biomolecules, polymers, organometallics, organics, inorganics, coordination molecules and nanomaterials. The interest in click chemistry is also a result of compatibility with the harshest conditions of reactions to provide stable, covalently linked entities. In recent years, researchers have employed this useful tool to fabricate systematic platforms that can produce the electrical signals to provide real data interpretation. It should be mentioned that various approaches to synthesis or fabrication of such systems have helped to develop this tool even further. These approaches include thiol addition, RIKEN click, aqueous click conjugation, copper(I)-catalyzed azide-alkyne cycloaddition (CuAAC), Strain-promoted azide-alkyne cycloaddition, etc. Unlike carbodiimide chemistry which is also very important but limited to the employment of crosslinkers in specific conditions, click chemistry allows reactions to take place even in the absence of catalysts. In this review, we explore the application of click chemistry in the fabrication of various materials and the electrochemical sensing platforms. Emphasis is put on CuAAC as one approach with which to afford these systems. The demonstration of electrochemical (bio)sensors is based on ‘on-electrode’ and ‘off-electrode’ design and architecture.