title: Ratiometric electrochemical immunoassay based on internal reference value for reproducible and sensitive detection of tumor marker.
abstract: A ratiometric assay in an electrochemical immunosensor for tumor marker, herein carcinoembryonic antigen (CEA) was chosen as a model analyte, was developed to improve simplicity and accuracy. The immunosensor was fabricated via the simple expedient way of using Polythionine-gold (PTh-Au) as electrode modified material to be an internal reference signal and K3[Fe(CN)6] in electrolyte as an indicator signal. When the CEA was fixed on the modified electrode via immunoreaction, only the indicator signal sensitively altered; by contrast, the internal reference signal of PTh-Au remained constant at a suitable pH of the electrolyte. The ratio between the alterations of the indicator signal of K3[Fe(CN)6] and the constant internal reference signal can be used to monitor the concentration of CEA reliably, reproducibly, and sensitively. The prepared ratiometric electrochemical immunosensor could detect CEA with good specificity within a wide linear range from 0.005ng/ml to 40ng/ml with a detection limit of 2.2pg/ml. Additionally, experimental results confirm that our proposed method is practical. Thus, this method can expand to recognize and test other protein markers.
authors.affiliation: Department of Pharmaceutical Analysis, Faculty of Pharmacy, the Higher Educational Key Laboratory for Nano Biomedical Technology of Fujian Province, Fujian Medical University, Fuzhou 350108, China.
authors.forename: Xiaohui
authors.initials: X
authors.lastname: Cai
authors.affiliation: Department of Pharmaceutical Analysis, Faculty of Pharmacy, the Higher Educational Key Laboratory for Nano Biomedical Technology of Fujian Province, Fujian Medical University, Fuzhou 350108, China. Electronic address: shweng@fjmu.edu.cn.
authors.forename: Shaohuang
authors.initials: S
authors.lastname: Weng
authors.affiliation: Department of Pharmaceutical Analysis, Faculty of Pharmacy, the Higher Educational Key Laboratory for Nano Biomedical Technology of Fujian Province, Fujian Medical University, Fuzhou 350108, China.
authors.forename: Rubin
authors.initials: R
authors.lastname: Guo
authors.affiliation: Department of Pharmaceutical Analysis, Faculty of Pharmacy, the Higher Educational Key Laboratory for Nano Biomedical Technology of Fujian Province, Fujian Medical University, Fuzhou 350108, China.
authors.forename: Liqing
authors.initials: L
authors.lastname: Lin
authors.affiliation: Department of Pharmaceutical Analysis, Faculty of Pharmacy, the Higher Educational Key Laboratory for Nano Biomedical Technology of Fujian Province, Fujian Medical University, Fuzhou 350108, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Chen
authors.affiliation: 476 Hospital of PLA, Fuzhou 350002, China.
authors.forename: Zongfu
authors.initials: Z
authors.lastname: Zheng
authors.affiliation: Department of Pharmaceutical Analysis, Faculty of Pharmacy, the Higher Educational Key Laboratory for Nano Biomedical Technology of Fujian Province, Fujian Medical University, Fuzhou 350108, China.
authors.forename: Zhengjun
authors.initials: Z
authors.lastname: Huang
authors.affiliation: Department of Pharmaceutical Analysis, Faculty of Pharmacy, the Higher Educational Key Laboratory for Nano Biomedical Technology of Fujian Province, Fujian Medical University, Fuzhou 350108, China. Electronic address: xhl1963@sina.com.
authors.forename: Xinhua
authors.initials: X
authors.lastname: Lin
mesh_terms: D014408:Biomarkers, Tumor / Q000097:blood; D015374:Biosensing Techniques / Q000295:instrumentation; D002272:Carcinoembryonic Antigen / Q000097:blood*; D055664:Electrochemical Techniques / Q000295:instrumentation*; D004566:Electrodes; D004867:Equipment Design; D006046:Gold / Q000737:chemistry; D006801:Humans; D007118:Immunoassay / Q000295:instrumentation*; D057230:Limit of Detection; D012016:Reference Values; D015203:Reproducibility of Results
chemical_list: D014408:Biomarkers, Tumor; D002272:Carcinoembryonic Antigen; D006046:Gold
keywords: Internal reference value; K(3)[Fe(CN)(6)]; Polythionine–gold; Ratiometric electrochemical immunoassay; Reproducible