A electro-thermal atomic absorption spectrometry-based assay for disease-related DNA

Electro-thermal atomic absorption spectrometry (ETAAS) is a powerful element detector, thanks to its low cost, high sensitivity, multiple element detectability, and low sample consumption. In this work, a simple and sensitive DNA assay utilizing ETAAS detection was demonstrated with Au nanoparticles (NPs) tag. Ebola Virus (EV)-related DNA was detected by sandwich hybridization assay, using Au NPs-labeled reporter probes and magnetic microparticle (MMP)-labeled capture probes. The sandwich hybridization reaction conditions were optimized. After hybridization reaction, aqua regia was added to dissolve Au NPs and release Au ions, which were subsequently detected by ETAAS. A good linearity was obtained between the concentration of target DNA and the atomic absorbance signal intensity. The limit of detection (LOD) was 3 pM (LOD, 3σ), with the linear range of 10-200 pM (R = 0.9933). The relative standard deviation (RSD) for 20 pM target DNA was 1.07%. The target DNA results obtained by the proposed method correlated well with those obtained by inductively coupled plasma-based hybridization assay.