A novel label-free voltammetric immunosensor for the detection of alpha-fetoprotein using functional titanium dioxide nanoparticles

作者：Liang Wen Bin; Yuan Ruo^*; Chai Ya Qin; Li Yan; Zhuo Ying

来源：Electrochimica Acta, 2008, 53(5): 2302-2308.

DOI：10.1016/j.electacta.2007.09.057

• 1.1'-Bis-(2-phosphonoethyl)-4.4'-bipyriclinium dibromide (PV) functional
• titanium dioxide nanoparticle (NTiP)
• gold nanoparticle (NGP)
• alpha-1-fetoprotein (AFP)
• immunosensor

A highly sensitive label-free voltammetric immunosensor was developed based on the functional titanium dioxide nanoparticles (PV-NTiP), which was prepared by capping 1,1'-bis-(2-phosphonoethyl)-4,4'-bipyridinium dibromide (PV) on the surface of the titanium dioxide nanoparticles (NTiP) with covalent attachment. The PV-NTiP has prominent biocompatibility, good electron transfer ability, primarily excellent adsorption, large specific surface area and positively charged environment. As a result, the negatively charged gold nanoparticles (NGP) could be adsorbed on the PV-NTiP modified electrode surface by electrostatic adsorption, and then to immobilize alpha- 1-fetoprotein antibody (anti-AFP) for the assay of alpha-1 fetoprotein (AFP). The fabricated procedures and electrochemical behaviors of the immunosensor were characterized by electrochemical impedance spectroscopy (EIS). scanning electron microscopy (SEM) and cyclic voltammetry (CV). The anti -AFP/NG P/PV-NTi P modified electrode was sensitive to AFP in linear relation between 1.25 and 200 ng/mL with the correlation coefficient of 0.9982, and the detection limit (S/N =3) is 0.6 ng/mL under the optimal conditions. In addition, the proposed immunosensor exhibits good sensitivity, selectivity, stability and long-term maintenance of bioactivity and it may be used to immobilize other biomoleculars to develop biosensor for the detection of other antigens or biocompounds.

• 出版日期2008-1-1
• 单位西南大学