A molecularly imprinted electrochemiluminescence sensor for ultrasensitive HIV-1 gene detection using EuS nanocrystals as luminophore

Development of simple, sensitive and specific method for human immunodeficiency virus (HIV) assays are urgently demand. In this study, we developed a novel molecularly imprinted polymer (MIP) electrochemiluminescence (MIP-ECL) sensor for the highly sensitive and selective HIV-1 gene detection using Europium sulfide nanocrystals (EsNCs) as signal producing compound. Here, the HIV aptamer as the template and o-phenylenediamine as the functional monomer, were electropolymerized directly on the surface of ITO electrode. With the hybridization reaction between the assemblies of EuS NCs functionalized 5-amino-labeled oligonucleotides as capture probes and oligonucleotides as detection target (HIV gene), the ECL signal significantly increased using K₂S₂O₈ as coreactant. Taking advantage of both MIP-ECL assays and the strong electrochemiluminescence emission of EuS NCs, the sensitive and selective HIV gene detection has been achieved in a linear range 3.0 fM to 0.3 nM with a detection limit of 0.3 fM. The present MIP-ECL biosensor showed good specificity for HIV DNA detection compared to non-complementary and two bases mismatched sequences. The proposed ECL biosensor was applied to detect of HIV DNA in real human serum samples and satisfactory results were obtained. Due to high sensitivity and selectivity, excellent reproducibility and stability of the proposed assay, EuS NCs can be used as novel luminophore for development of MIP-ECL sensors for detection of other DNA biomarkers.