Gold Nanoparticle-Based Quantitative Electrochemical Detection of Amplified Human Cytomegalovirus DNA Using Disposable Microband Electrodes

An electrochemical DNA detection method has been developed for the sensitive quantification of an amplified 406-base pair human cytomegalovirus DNA sequence (HCMV DNA). The assay relies on (i) the hybridization of the single-stranded target HCMV DNA with an oligonucleotide-modified Au nanoparticle probe, (ii) followed by the release of the gold metal atoms anchored on the hybrids by oxidative metal dissolution, and (iii) the indirect determination of the solubilized Au<sup>III</sup> ions by anodic stripping voltammetry at a sandwich-type screen-printed microband electrode (SPMBE). Due to the enhancement of the Au<sup>III</sup> mass transfer by nonlinear diffusion during the electrodeposition time, the SPMBE allows the sensitive determination of Au<sup>III</sup> in a small volume of quiescent solution. The combination of the sensitive Au<sup>III</sup> determination at a SPMBE with the large number of Au<sup>III</sup> released from each gold nanoparticle probe allows detection of as low as 5 pM amplified HCMV DNA fragment.