Surface chemistry applications and development of immunosensors using electrochemical impedance spectroscopy: A comprehensive review

Immunosensors are promising alternatives as detection platforms for the current gold standards methods. Electrochemical immunosensors have already proven their capability for the sensitive, selective, detection of target biomarkers specific to COVID-19, varying cancers or Alzheimer's disease, etc. Among the electrochemical techniques, electrochemical impedance spectroscopy (EIS) is a highly sensitive technique which examines the impedance of an electrochemical cell over a range of frequencies. There are several important critical requirements for the construction of successful impedimetric immunosensor. The applied surface chemistry and immobilisation protocol have impact on the electroanalytical performance of the developed immunosensors. In this Review, we summarise the building blocks of immunosensors based on EIS, including self-assembly monolayers, nanomaterials, polymers, immobilisation protocols and antibody orientation.

Automated summary

Immunosensors are promising alternatives to current gold standard methods in detection. Electrochemical immunosensors have demonstrated their capability for sensitive and selective detection of specific biomarkers related to COVID-19, various cancers, Alzheimer's disease, etc. Among the electrochemical techniques, electrochemical impedance spectroscopy (EIS) is a highly sensitive method that examines impedance over a range of frequencies in an electrochemical cell. The construction of successful impedimetric immunosensors requires important factors such as surface chemistry and immobilization protocols that impact the electroanalytical performance. In this Review, we summarize the building blocks of EIS-based immunosensors, including self-assembly monolayers, nanomaterials, polymers, immobilization protocols, and antibody orientation.