Development of DNA Biosensor Based on TiO_2 Nanoparticles

摘要

A novel technique of DNA hybridization on the TiO_2 nanoparticles film was developed by dropping a single droplet of target DNA onto the surface of TiO_2 for the study of various concentrations of target DNA. The surface of TiO_2 nanoparticle film was functionalized with APTES and covalently immobilized with 1 μM probe DNA on the silanized TiO_2 nanoparticles surface. The effect of silanization, immobilization and hybridization were quantitatively measured by the output current signal obtained using a picoammeter. The 1 μM target DNA was found to be the most effective target towards the 1μM probe DNA as the output current signal was within range; while the output current signal of the 10 μM target DNA was observed to beyond the range of the probe DNA control due to the excessive concentration as compared to the probe DNA. This approach has several advantages such as rapid, simple, low cost, and sensitive current signal during detection of different target DNA concentrations.