Paper-based electrochemical biosensors for the diagnosis of viral diseases

Paper-based electrochemical analytical devices (ePADs) have gained significant interest as promising analytical units in recent years because they can be fabricated in simple ways, are low-cost, portable, and disposable platforms that can be applied in various fields. In this sense, paper-based electrochemical biosensors are attractive analytical devices since they can promote diagnose several diseases and potentially allow decentralized analysis. Electrochemical biosensors are versatile, as the measured signal can be improved by using mainly molecular technologies and nanomaterials to attach biomolecules, resulting in an increase in their sensitivity and selectivity. Additionally, they can be implemented in microfluidic devices that drive and control the flow without external pumping and store reagents, and improve the mass transport of analytes, increasing sensor sensitivity. In this review, we focus on the recent developments in electrochemical paper-based devices for viruses' detection, including COVID-19, Dengue, Zika, Hepatitis, Ebola, AIDS, and Influenza, among others, which have caused impacts on people's health, especially in places with scarce resources. Also, we discuss the advantages and disadvantages of the main electrode's fabrication methods, device designs, and biomolecule immobilization strategies. Finally, the perspectives and challenges that need to be overcome to further advance paper-based electrochemical biosensors' applications are critically presented.

Automated summary

Paper-based electrochemical analytical devices (ePADs) have gained significant interest due to their simplicity, low cost, portability, and applicability in various fields. Electrochemical biosensors, especially those based on paper, offer attractive advantages such as disease diagnosis and decentralized analysis. This review focuses on recent advancements in paper-based electrochemical devices for detecting viruses, including COVID-19, Dengue, Zika, Hepatitis, Ebola, AIDS, and Influenza, and discusses fabrication methods, device designs, and biomolecule immobilization strategies. The challenges and perspectives for further applications of paper-based electrochemical biosensors are also critically addressed.