Electrochemical Detection of dsDNA-Specific Antibodies

Electrochemical biosensors have shown great promise as useful point-of-care tests since they operate on electronic circuits which can be miniaturized and whose readout process can be easily automated. Here, we describe a method for the electrochemical sensing of antibodies directed against double-stranded DNA (α-dsDNA), which are often present at higher-than-normal levels in the sera of autoimmune disease patients. The method can be easily implemented in any lab and requires little investment in equipment, namely a potentiostat. An artificial reference serum sample containing known amounts of spiked-in α-dsDNA antibodies enables reporting results in absolute scale rather than titer. Once electrodes are modified with DNA and the calibration curves are made (i.e., after the biosensor construction phase), individual measurements in test samples can be obtained in as low as 35 min.