A Molecular Switch Framework for Reagentless Electrochemical Detection of Proteins

Abstract

Reagentless electrochemical protein detection is critical for real-time health monitoring. Most currently available electrochemical antibody-based sensors require the addition of external reagents as redox reporters and/or detection antibodies. Here, we introduce ProSwitch, a protein detection sensor that offers an electrochemical and reagentless method of target analyte detection. ProSwitch operates using a molecular switch mechanism, leveraging antibodies and ferrocenetagged antigens attached to an electrode surface via polyethylene glycol (PEG) arms. Protein detection is achieved through an antigen competition strategy, where the target antigen competes with the tagged antigen for binding, generating a measurable electrochemical signal. Tests with various large and small proteins confirmed ProSwitch's broad operational range across diverse proteins, demonstrating its potential suitability for use in biological fluids and health monitoring applications.