TY - JOUR
T1 - Ultrasensitive enzyme-free electrochemical immunoassay for free thyroxine based on three dimensionally ordered macroporous chitosan-Au nanoparticles hybrid film
AU - Zhang, Qi
AU - Chen, Xiaojun
AU - Tu, Fulai
AU - Yao, Cheng
PY - 2014/9/15
Y1 - 2014/9/15
N2 - The measurement of free thyroxine concentration in serum is considered to be an essential indicator of thyroid function. Here, a novel enzyme-free sandwich electrochemical immunosensor for the detection of FT4 antigen based on the immobilization of primary antibody (Ab1) on three dimensional ordered macroporous chitosan-Au nanoparticles hybrid (3DOM CS-AuNPs) film electrode, and magnetic multiwall carbon nanotubes (MMWCNTs) were used as label of secondary antibody (Ab2). The 3DOM CS-AuNPs film electrode was constructed by one-step electrodeposition of CS-AuNPs composite onto Au electrode with silica opal template. MMWCNTs were prepared by chemical co-precipitation of Fe2+ and Fe3+ salts on carboxylated MWCNTs. Ru(bpy)32+ labeled anti-FT4 (Ru(bpy)32+-Ab2) was covalently attached to MMWCNTs through the formation of amide bond between the carboxylic groups of MWCNTs and the amine groups of antibody. Under the optimal conditions, FT4 was detected in a concentration range from 0.71fgmL-1 to 1.15pgmL-1 with a correlation coefficient of 0.998 and a detection limit of 0.20fgmL-1. Moreover, the immunosensor showed excellent selectivity, good stability, satisfactory reproducibility and regeneration. Importantly, the developed method was used to assay clinical serum specimens, achieving a good relation with those obtained from the commercialized electrochemiluminescent method.
AB - The measurement of free thyroxine concentration in serum is considered to be an essential indicator of thyroid function. Here, a novel enzyme-free sandwich electrochemical immunosensor for the detection of FT4 antigen based on the immobilization of primary antibody (Ab1) on three dimensional ordered macroporous chitosan-Au nanoparticles hybrid (3DOM CS-AuNPs) film electrode, and magnetic multiwall carbon nanotubes (MMWCNTs) were used as label of secondary antibody (Ab2). The 3DOM CS-AuNPs film electrode was constructed by one-step electrodeposition of CS-AuNPs composite onto Au electrode with silica opal template. MMWCNTs were prepared by chemical co-precipitation of Fe2+ and Fe3+ salts on carboxylated MWCNTs. Ru(bpy)32+ labeled anti-FT4 (Ru(bpy)32+-Ab2) was covalently attached to MMWCNTs through the formation of amide bond between the carboxylic groups of MWCNTs and the amine groups of antibody. Under the optimal conditions, FT4 was detected in a concentration range from 0.71fgmL-1 to 1.15pgmL-1 with a correlation coefficient of 0.998 and a detection limit of 0.20fgmL-1. Moreover, the immunosensor showed excellent selectivity, good stability, satisfactory reproducibility and regeneration. Importantly, the developed method was used to assay clinical serum specimens, achieving a good relation with those obtained from the commercialized electrochemiluminescent method.
KW - Chitosan-Au nanoparticles hybrid film
KW - Free thyroxine
KW - Magnetic multiwall carbon nanotubes
KW - Sandwich-type electrochemical immunosensor
KW - Three dimensionally ordered macroporous materials
UR - http://www.scopus.com/inward/record.url?scp=84898949346&partnerID=8YFLogxK
U2 - 10.1016/j.bios.2014.03.068
DO - 10.1016/j.bios.2014.03.068
M3 - 文章
C2 - 24752149
AN - SCOPUS:84898949346
SN - 0956-5663
VL - 59
SP - 377
EP - 383
JO - Biosensors and Bioelectronics
JF - Biosensors and Bioelectronics
ER -