Utilizing Electrochemical Methods to Determine Reaction Rates on Paper Media

Biosensors have become a prominent field of research in a world where detection is one of the key methods to prevent spread of disease and obtain medical information in a patient. One of the most cost-effective ways to currently do this involves paper-based analytical devices which provide quick feedback on an analyte of interest. The commonly used method, a lateral flow assay with a colorimetric readout, has currently been one of the key proponents of the field with constant research being done on this subject. However, significant limitations to this method are the sensitivity of the test as well as an immobilization requirement for the reactant, requiring extra steps. We suggest combining paper-based devices with a previously established readout method, transient induced molecular electronic signal (TIMES), which uses electrochemical signals to determine if a reaction has occurred. By reading the induced charge that comes from the chemical reaction or analyte being observed, immobilization of the analyte can be bypassed. Furthermore, a direct signal can be generated and analyzed to confirm results rather than relying on a weak colorimetric readout. This method will not only lower the amount, and therefore, cost of the material being used, but also simplify the overall process by skipping the immobilization step. In this paper, we use this method to study protein and antibody binding interactions to confirm the validity of this technique. By showing how the results fit to kinetic standards, we can open up the opportunity for further studies on this method.