title: An electrochemical immunosensor for ultrasensitive detection of carbohydrate antigen 199 based on Au@Cu(x)OS yolk-shell nanostructures with porous shells as labels.
abstract: A novel and sensitive electrochemical immunosensor for ultrasensitive detection of pancreatic cancer biomarker carbohydrate antigen 199 (CA199) was proposed by using Au@Cu(x)OS yolk-shell nanostructures with porous shells as labels for signal amplification. Au@Cu(x)OS 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@Cu(x)OS 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 12 U/mL with a low detection limit of 0.0005 U/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.
authors: Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong (University of Jinan), School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, PR China.
authors: Aiping
authors: A
authors: Guo
authors: School of Chemical Engineering, Shandong University of Technology, Zibo 255049, PR China.
authors: Yueyun
authors: Y
authors: Li
authors: Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong (University of Jinan), School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, PR China.
authors: Wei
authors: W
authors: Cao
authors: Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong (University of Jinan), School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, PR China.
authors: Xianchao
authors: X
authors: Meng
authors: Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong (University of Jinan), School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, PR China.
authors: Dan
authors: D
authors: Wu
authors: Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong (University of Jinan), School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, PR China. Electronic address: sdjndxwq@163.com.
authors: Qin
authors: Q
authors: Wei
authors: Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong (University of Jinan), School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, PR China.
authors: Bin
authors: B
authors: Du
mesh_terms: D015295:Antigens, Tumor-Associated, Carbohydrate / Q000097:blood / Q000737:chemistry / Q000302:isolation & purification*; D014408:Biomarkers, Tumor / Q000097:blood / Q000737:chemistry / Q000302:isolation & purification*; D015374:Biosensing Techniques / Q000379:methods*; D006046:Gold / Q000737:chemistry; D006108:Graphite / Q000737:chemistry; D006801:Humans; D006861:Hydrogen Peroxide / Q000737:chemistry; D053768:Metal Nanoparticles / Q000737:chemistry*
chemical_list: D015295:Antigens, Tumor-Associated, Carbohydrate; D014408:Biomarkers, Tumor; C578959:carbohydrate antigen 199, human; D006046:Gold; D006108:Graphite; D006861:Hydrogen Peroxide
keywords: Au nanoparticles; Au@Cu(x)OS yolk–shell nanostructures with porous shells; Pancreatic cancer biomarker CA199; Reduced graphene oxide–tetraethylene pentamine (rGO–TEPA)