Strategies to Enable Practical Electrochemical Diagnostics for Proteins and Small Molecules

Despite decades of research into biosensors ‐ sensors based on biological interactions ‐ few have made the transition from the academic lab to practical diagnostic use in industry or the clinic. One common biosensor class utilizes electrochemical detection of changes in oligonucleotide structure upon binding to a target protein or small molecule. To make widespread adoption of this large class of biosensors more feasible, we have pursued multiple approaches to address typical shortcomings of biosensor design and performance. These include: the design and implementation of an oligonucleotide folding evaluation webserver, Fealden, which can identify sequences and folding patterns likely to yield significant signal response; investigations of surface passivation and hydrogel filtration to enable functional analysis of binding interactions in unprocessed whole blood; and automated signal analysis software to enable rapid turnaround from raw biosensor signal to reportable quantification of target. As proof of concept, we have applied these tools to design, generate, and test biosensors directed against the protein toxins in botulism and ricin poisoning, which are currently typically detected only with slow, cumbersome, and/or error‐prone diagnostics. This work thus provides insights into a multifaceted approach to utilize the wide pool of existing biosensors in practical applications ranging across food safety, environmental monitoring, and clinical diagnostics.