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.