Electrochemical biosensors are superior technologies that are used to detect or sense biologically and environmentally significant analytes in a laboratory environment, or even in the form of portable handheld or wearable electronics. Recently, imprinted and implantable biosensors are emerging as point-of-care devices, which monitor the target analytes in a continuous environment and alert the intended users to anomalies. The stability and performance of the developed biosensor depend on the nature and properties of the electrode material or the platform on which the biosensor is constructed. Therefore, the biosensor platform plays an integral role in the effectiveness of the developed biosensor. Enormous effort has been dedicated to the rational design of the electrode material and to fabrication strategies for improving the performance of developed biosensors. Every year, in the search for multifarious electrode materials, thousands of new biosensor platforms are reported. Moreover, in order to construct an effectual biosensor, the researcher should familiarize themself with the sensible strategies behind electrode fabrication. Thus, we intend to shed light on various strategies and methodologies utilized in the design and fabrication of electrochemical biosensors that facilitate sensitive and selective detection of significant analytes. Furthermore, this review highlights the advantages of various electrode materials and the correlation between immobilized biomolecules and modified surfaces.

A simple and selective enzyme-free electrochemical sensor for H₂O₂ has been designed and fabricated using ionic liquid (IL) tagged anthraquinone (AQ) modified electrode (AQ-PF₆-IL). This newly synthesized AQ-PF₆-IL has been systematically characterized, after which it has been immobilized over a screen-printed electrode to produce AQ-PF₆-IL/SPE. The electrochemical investigation of AQ-PF₆-IL/SPE displayed a set of distinct redox peaks attributable to the anthraquinone/anthrahydroquinone redox pair. Interestingly, AQ-PF₆-IL/SPE has shown enhanced peak current at reduced formal potential for AQ, when compared to AQ/SPE. Further, the electrocatalytic activity of AQ-PF₆-IL/SPE towards the reduction of H₂O₂ was investigated with the sequential addition of H₂O₂. A rapid and appreciable enhancement in cathodic peak currents was observed and thus demonstrating the excellent electrochemical reduction of H₂O₂ at the newly developed sensor. Besides, AQ-PF₆-IL/SPE established a good linear behaviour over a concentration range of 10–1228 μM with a high sensitivity of 0.281 μA μM⁻¹ cm⁻² and low detection limit of 2.87 μM. The fabricated sensor displayed excellent stability, good anti-interference ability, along with acceptable reproducibility. The superior properties of the developed sensor could be attributed to the newly designed AQ-PF₆-IL, wherein the redox characteristics of AQ mediator are integrated with the high stability and conductivity of IL.