An electrochemical DNA biosensor developed on novel multinuclear nickel(II) salicylaldimine metallodendrimer platform

作者：Arotiba Omotayo A; Ignaszak Anna; Malgas Rehana; Al Ahmed Amir; Baker Priscilla G L; Mapolie Selwyn F; Iwuoha Emmanuel I^*

来源：Electrochimica Acta, 2007, 53(4): 1689-1696.

DOI：10.1016/j.electacta.2007.08.016

• dendrimer
• metallodendrimer
• electrochemical DNA biosensor
• immobilization
• electrochemical impedance spectroscopy

An electrochemical DNA biosensor (EDB) was prepared using an oligonucleotide of 21 bases with sequence NH2-5'-GAGGAGTTGGGGGAGCACATT-3' (probe DNA) immobilized on a novel multinuclear nickel(II) salicylaldimine metallodendrimer on glassy carbon electrode (GCE). The metallodendrimer was synthesized from amino functionalized polypropylene imine dendrimer, DAB-(NH2)(8). The EDB was prepared by depositing probe DNA on a dendrimer-modified GCE surface and left to immobilize for 1 h. Voltammetric and electrochemical impedance spectroscopic (EIS) studies were carried out to characterize the novel metallodendrimer, the EDB and its hybridization response in PBS using [Fe(CN)(6)](3-/4-) as a redox probe at pH 7.2. The metallodendrimer was electroactive in PBS with two reversible redox couples at E degrees' = +200 mV and E degrees' = +434 mV; catalytic by reducing the E-pa of [Fe(CN)(6)](3-/4-) by 22 mV; conducting and has diffusion coefficient of 8.597 x 10(-1) cm(2) s(-1). From the EIS circuit fitting results, the EDB responded to 5 nM target DNA by exhibiting a decrease in charge transfer resistance (R-ct) in PBS and increase in R-ct in [Fe(CN)(6)](3-/4-) redox probe; while in voltammetry, increase in peak anodic current was observed in PBS after hybridization, thus giving the EDB a dual probe advantage.

• 出版日期2007-12-31