A reusable DNA biosensor for the detection of genetically modified organism using magnetic bead-based electrochemiluminescence

A reusable magnetic bead-based electrochemiluminescence (ECL) DNA biosensor for the detection of genetically modified organism (GMO) is proposed. The sensor method consists of immobilization of biotin-probe using streptavidin-coated magnetic beads, hybridization of target DNA with biotin-probe and ruthenium(II) tris-bipyridal (TBR)-probe, detection of target DNA by direct measuring the ECL emission of TBR. The sensor was applied to detect GMO in engineered tobacco samples. Results indicate that the sensitivity of this sensor method was 5 nmol/L of CaMV35S DNA. A stable calibration curve with a wide dynamic range was established. The calibration curve was linear from 5 nmol/L to 5 μmol/L, thus, made quantitative analysis possible. GM tobacco samples and non-GM tobacco samples were clearly discriminated by the sensor method. Results of the study suggest that the reusable DNA biosensor is a feasible tool for daily GMO detection due to its rapidness, simplicity, safety, sensitivity, reliability and low cost.