标题：An electrochemical immunosensor for ultrasensitive detection of carbohydrate antigen 199 based on Au@CuxOS yolk-shell nanostructures with porous shells as labels
作者：Guo, Aiping ;Li, Yueyun ;Cao, Wei ;Meng, Xianchao ;Wu, Dan ;Wei, Qin ;Du, Bin
作者机构：[Guo, Aiping ;Cao, Wei ;Meng, Xianchao ;Wu, Dan ;Wei, Qin ;Du, Bin ] Key Laboratory of Chemical Sensing and Analysis in Universities of Shandong (Univ 更多
来源：Biosensors and Bioelectronics
摘要：A novel and sensitive electrochemical immunosensor for ultrasensitive detection of pancreatic cancer biomarker carbohydrate antigen 199 (CA199) was proposed by using Au@CuxOS yolk-shell nanostructures with porous shells as labels for signal amplification. Au@CuxOS yolk-shell nanostructures exhibit high electrocatalytic activity toward the reduction of hydrogen peroxide (H2O2) as analytical signal. Moreover, secondary antibody (Ab2) can adsorb on the surface of Au@CuxOS with porous shells which has large surface area and could greatly increase the probability of Ab2-antigen interactions thereby leading to higher sensitivity. Reduced graphene oxide-tetraethylene pentamine (rGO-TEPA), containing abundant amine groups, was supported Au nanoparticles as a support platform to immobilize the primary antibody (Ab1). The resulting sensing interface of rGO-TEPA/AuNPs could provide a large electroconductive surface area, allowing high loadings of the biological recognition elements as well as the occurrence of electrocatalytic and electron-transfer processes. Under optimal conditions, the immunosensor exhibited a wide linear response to CA199 ranging from 0.001 to 12U/mL with a low detection limit of 0.0005U/mL. The designed immunosensor displayed good precision, high sensitivity, acceptable stability and reproducibility, and has been applied to the analysis of serum with satisfactory results. The proposed method provides a new promising platform of clinical immunoassay for other biomolecules.
© 2014 Elsevier B.V.