An Nb-doped Nickel Oxide–Carbon Nanotubes Composite- Enhanced Electrochemical DNA Biosensor for Detection of Lead(II) Ion

摘要

A novel niobium doped nickel oxide nanoparticle (NbNiO) was synthesized by sol-gel method and2+ was applied to fabricate DNA biosensor for detection of Pb in water sample for the first time. Theamino-modified G-rich DNA probes were immobilized on the surface of CH-NbNiO-MWCNTs/ITOelectrode by the covalent interaction between the amino of DNA and the carboxyl of MWCNTs. When2+ the lead (II) ion (Pb ) interacted with the G-rich DNA, it will induce the DNA conformational toswitch from a random-coil to a G-quadruplex resulting in an increase of alternating current impedance.2+ On the basis of this, we developed an impedance biosensor for the detection of Pb . The resultsshowed that the synergistic effect of the synthesized NbNiO nanoparticles and MWCNs could improvethe performance of this DNA biosensor. Under optimal conditions, the fabricated DNA biosensor-10 -5possess a wide linear range of 1.010 to 1.010 M (correlation coefficient, R=0.998) and a low-12 detection limit of 7.51 10 M (3).