This review highlighted methods for immobilising an antibody or antigen bioreceptor to an electrode surface for the development of an immunosensor. The focus was EIS-based sensors which facilitate label-free sensing, reducing the complexity of the assay and providing a path towards POC. Faradaic or non-faradaic modes of detection were discussed. Faradaic impedance has shown dominance in research, however non-Faradaic is employed as it does not require redox probes and is especially gaining popularity when carried out with IDEs. Immunosensors can be applied for disease diagnostics in both humans and animals, as well as in the food security sector. Recent research has shown progress in developing POC towards these sectors. Incubations times are being reduced, microfluidics offer the possibility of multiple sample testing and single frequency analysis allows for real-time monitoring of the antibody/antigen binding.