Signal transduction with a swing

Abstract

The continuous monitoring of proteins is a current challenge in medical diagnostics. A new electrochemical approach aiming to address this has been described. The method uses antibodies as a recognition element to achieve the real-time measurement of proteins in saliva in the mouth.

Figure 1.

The inverted pendulum approach converts antibody binding into an electrochemical signal in a reversible manner and without the use of reagents. It is composed of a short, double-stranded DNA scaffold that is attached to an electrode and modified on its distal end with an antibody and a redox reporter. When the electrode is held at a positive potential (time = t₁), the negatively-charged pendulum is attracted to the surface, but the kinetics with which it approaches are modulated by the hydrodynamic size of the target. Specifically, the target-free pendulum (left) migrates to the surface more rapidly than the target-bound pendulum (right), thus causing the observed electron transfer rate to depend on receptor occupancy. Created with BioRender.com