A new dual immunoassay for tumor markers based on chemiluminescence signal amplification by magnetic mesoporous silica and enzyme modified gold nanoparticles.
A sensitive dual immunoassay was proposed for the determination of carcinoembryonic antigen (CEA) and α-fetoprotein (AFP) based on signal amplification.  Monoclonal antibodies immobilized on magnetic mesoporous silica particles (Fe(3)O(4)/SiO(2)) were prepared as the primary probe.  Horseradish peroxidase (HRP) labeled antibodies co-coated with HRP on gold nanoparticles (AuNPs) were used as the secondary probe to achieve signal amplification.  HRP tags were retained in the flow cells after a sandwich immunoassay.  By controlling two switches on the two channels, chemiluminescent substrates were injected orderly man way, and then signals for CEA and AFP were sequentially detected by HRP-luminol-H(2)O(2).  Due to the increased amount of HRP on AuNPs and the increased amount of monoclonal antibodies on Fe(3)O(4)/SiO(2), the signals were largely amplified.  Under the optimal conditions, CEA and AFP could be detected in the linear ranges of 1.0 - 80 and 1.0 - 75 ng mL(-1) with detection limits of 0.25 and 0.5 ng mL(-1), respectively.
Key Laboratory of Eco-chemical Engineering, Ministry of Education, College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, PR China. linjiehua@qust.edu.cn
Jiehua
J
Lin
Pengfei
P
Chu
Zhijing
Z
Wei
D014408:Biomarkers, Tumor / Q000032:analysis*; D002272:Carcinoembryonic Antigen / Q000032:analysis; D006046:Gold / Q000737:chemistry*; D006735:Horseradish Peroxidase / Q000737:chemistry* / Q000378:metabolism; D007118:Immunoassay / Q000295:instrumentation / Q000379:methods*; D049449:Luminescence; D060328:Magnetic Phenomena; D053768:Metal Nanoparticles / Q000737:chemistry*; D016062:Porosity; D012822:Silicon Dioxide / Q000138:chemical synthesis / Q000737:chemistry*; D013499:Surface Properties; D000509:alpha-Fetoproteins / Q000032:analysis
D014408:Biomarkers, Tumor; D002272:Carcinoembryonic Antigen; D000509:alpha-Fetoproteins; D006046:Gold; D012822:Silicon Dioxide; D006735:Horseradish Peroxidase