Enzyme-free electrochemical aptasensor by using silver nanoparticles aggregates coupling with carbon nanotube inducing signal amplification through electrodeposition
A novel and enzyme-free electrochemical aptasensor based on magnetic separation platform was designed for highly sensitive determination of PDGF-BB by virtue of utilizing catalytic activity of silver nanoparticles (AgNPs) towards the reduction of o-nitrophenol (o-NP) to o-aminophenol (o-AP) by NaBH4,and the direct electric readout from the product of electrodeposition of o-AP and multiwalled carbon nanotubes (MWCNTs) on screen printed electrode (SPE).Aptamers functionalized magnetic beads (apt-MBs) were used as capture probe,while AgNPs modified with aptamers and hybrid probes (apt-AgNPs-A and apt-AgNPs-B) were used as tags.In the presence of PDGF-BB,the apt-MBs and the AgNPs aggregates which were induced by in-situ hybridization of apt-AgNPs-A and apt-AgNPs-B formed a sandwich-like complex,followed by adding of NaBH4 and o- NP.Owing to the amplified catalysis of AgNPs aggregates conjugated in the complex,the o-NP was reduced by NaBH4 to o-AP,which was electro-co-deposition with MWCNTs on the SPE,producing a conducting nanocomposite.The signal readout in this aptasensor for PDGF-BB was obtained by direct measurement of the poly(o-AP-MWCNTs) film on the SPE.Using this signal transduction protocol,the analytical performance of the electrochemical aptasensor was studied in detail.Under the optimal conditions,the assay displayed a wide dynamic working range of between 0.1 ng mL-1 and 100 ng mL-1 with a detection limit of 60 pg mL-1 relative to target PDGF-BB.Incorporation of good catalytic ability of hybridization inducing AgNPs aggregates and excellent electrochemical property of poly(o-AP-MWCNTs) nanocomposite could result in the amplification of the electrochemical signal,owing to the high loading of catalytic AgNPs and electro-co-deposition of MWCNTs.This method would have a promising future for application in clinical diagnostics.
Electrochemical aptasensor Silver nanoparticles Magnetic beads Catalytic reduction Electrodeposition Multiwalled carbon nanotubes
Wei Song Qiqi Niu Weibing Qiang Hui Li Danke Xu
State Key Laboratory of Analytical Chemistry for Life Science,School of Chemistry and Chemical Engin State Key Laboratory of Analytical Chemistry for Life Science,School of Chemistry and Chemical Engin
国际会议
南京
英文
62-69
2016-12-23（万方平台首次上网日期，不代表论文的发表时间）