Hybridization biosensor based on the covalent immobilization of probe DNA on chitosan-mutiwalled carbon nanotubes nanocomposite by using glutaraldehyde as an arm linker

摘要: Abstract A label-free DNA biosensor for hybridization detection of short species related to the transgenic plants gene fragment cauliflower mosaic virus (CaMV) 35S promoter was developed in this paper. The nanocomposite containing chitosan (CS) and mutiwalled carbon nanotubes (MWNTs) first coated on a glassy electrode. Then highly reactive dialdehyde reagent glutaraldehyde (GTD) applied as an arm linker covalently graft 5′-amino modified probe CS–MWNTs surface via facile aldehyde–ammonia condensation reaction. capacity monitored with electrochemical impedance spectroscopy (EIS) using [Fe(CN)6]3−/4− indicating probe, experimental results showed that had fast rate low background interference. wide dynamic range (1.0 × 10−13–5 × 10−10 M) limit (8.5 × 10−14 M) were achieved complementary sequence. In addition, specificity experiments sensing system can accurately discriminate sequence from mismatch noncomplementary sequences.