Abstract

Electrochemical genosensors for the ultra-trace determination of label-free DNA hybridization with ultrahigh sensitivity, low cost, specifific selectivity and fast analysis can be developed for cancer diagnosis and food science in complicated samples using a variety of gold (Au) nanomaterials and their three-dimensional (3D) nanoarchitectures as well as layer-by-layer (LBL) assembly. We explored the LBL assembled gold nanoparticles (AuNPs)/lower-generation (Gn≤3) polyamidoamine dendrimer (PD) with the reduced graphene oxide (rGO) core as electrochemical gene nanobiosensing platforms with 3D fractal nanoarchitecture for fast, ultra-trace determination of label-free DNA hybridization. Their morphologies, structures, electrochemical properties, and gene nanobiosensing performances were characterized. AuNPs/GG2PD displayed the best excellent structural stability, lowest mobility on solid surface with the increasing charge resistance, widest linear range (1.1 × 10−6 – 1 × 10−18), and the lowest limit of detection (1.87 × 10−19 M) in comparison with both AuNPs/GG1PD-based and AuNPs/GG3PD-based probes. This work will provide a new candidate for the development of metal nanoparticles functionalized PD with inorganic nonmetallic nanomaterials as cores with 3D fractal nanoarchitecture and promising electrochemical gene nanobiosensing platforms based on dendrimer- nanoinorganic hybrids with 3D nanoarchitectures and LBL assembly for fast and ultra-trace detection of lab -free DNA hybridization with potential application in bioanalysis and medical diagnosis of genetic diseases.