Enzyme-Linked DNA Displacement (ELIDIS) Assay for Ultrasensitive Electrochemical Detection of Antibodies

Here we report the development of a method for the electrochemical ultrasensitive detection of antibodies that couples the programmability and versatility of DNA-based systems with the sensitivity provided by enzymatic amplification. The platform, termed Enzyme-Linked DNA Displacement (ELIDIS), is based on the use of antigen-DNA conjugates that, upon the bivalent binding of a specific target antibody, induce the release of an enzyme-DNA hybrid strand from a preformed duplex. Such enzyme-DNA hybrid strand can then be electrochemically detected with a disposable electrode with high sensitivity. We applied ELIDIS to demonstrate the sensitive (limit of detection in the picomolar range), specific and multiplexed detection of five different antibodies including three clinically relevant ones. ELIDIS is also rapid (it only requires two reaction steps), works well in complex media (serum) and is cost-effective. A direct comparison with a commercial ELISA kit for the detection of Cetuximab demonstrates the promising features of ELIDIS as a point-of-care platform for antibodies detection. We demonstrate the ultrasensitive, specific, selective and multiplexed detection of different antibodies in blood serum using a strategy that couples the programmability and versatility of DNA-based systems with the sensitivity provided by enzymatic amplification.**image

Automated summary

We have developed a method, called Enzyme-Linked DNA Displacement (ELIDIS), for the electrochemical ultrasensitive detection of antibodies. ELIDIS combines the programmability and versatility of DNA-based systems with the sensitivity provided by enzymatic amplification. It has been shown to be sensitive, specific, and efficient in detecting multiple antibodies in complex media, making it a promising platform for point-of-care antibody detection.