TiO2-guanine as a new amalgamation compound for fabrication of a disposable biosensor with high sensitivity and rapid detection of H1N1 swine flu virus

Abstract

A TiO₂-guanine nanocomposite (TG NC)-based electrochemical biosensor was immobilized with hemagglutinin (HA) gene specific probe with 5' NH₂ group on screen-printed gold electrode (probe(ss)DNA-TG-SPGE). The modified biosensor was examined for H1N1 swine flu virus. TG NCs along with precursors were characterized spectroscopically and morphologically by employing several approaches. Electrochemical investigations were performed with the help of cyclic voltammetric (CV) and electrochemical impedance spectroscopy (EIS) in 0.1 M phosphate buffer saline (PBS; pH 7.4) with 1 µM methylene blue (MB) redox indicator. For better detection of single-stranded virus DNA, the modified electrode was optimized at various concentrations, pH, and scan rates. The modified biosensor showed high sensitivity (40.32 μA/ng.cm²), low LOD (0.00024 ng/6 µL), and broad linear range 0.0002-20 ng/6µL with coefficient of determination of R²=0.9981 for H1N1 virus detection. The HA gene-modified biosensor presented decent stability and specificity against different infectious pathogens including H3N2 virus and human DNA with negative response. Furthermore, the modified biosensor also responded well for real sample target DNA detection with a recovery of >96%. The simply designed HA gene-modified biosensor transduces decreased current response towards target-specific (ss)DNA binding and could be used as a rapid detection tool for H1N1 swine flu virus diagnosis.

Keywords: Cyclic voltammetry; Electrochemical analysis; H1N1 biosensor; Influenza virus; Screen-printed gold electrode; TiO2-guanine nano-combination.