Highly sensitive colorimetric immunosensor for influenza virus H5N1 based on enzyme-encapsulated liposome.
Development of simple but sensitive biosensor for influenza detection is highly important in immediate and effective clinical treatment. In this study, a sensitive colorimetric immunosensor which combines the advantages of high selectivity of immunoassay and simplicity of colorimetric detection has been developed to detect influenza virus H5N1 based on enzyme-encapsulated liposome. Biotin-tagged liposome encapsulated with large amount of horseradish peroxidase (HRP) was firstly synthesized. In the presence of H5N1, H5N1 co-bound with the capture antibody and the biotinylated detection antibody to form sandwich immunocomplex. Subsequently, the HRP-encapsulated liposome was introduced to conjugate with the detection antibody through biotin-avidin-biotin linkage. Upon the addition of substrate (mixture of 3,3',5,5'-tetramethylbenzidine (TMB) and H2O2), the liposome was directly lysed to release large amount of HRP by TMB. The released HRP catalyzed the H2O2-mediated oxidation of TMB, resulting in color change of the system, which was observed by naked eyes or UV-vis spectra. The result showed that the absorption intensity enhanced with the increase of H5N1 concentration ranging from 0.1 to 4.0 ng/mL, and the detection limit was calculated to be 0.04 ng/mL. The sensitivity of the proposed biosensor is much higher than that of conventional enzyme-linked immunosorbent assay method. The proposed immunosensor is relatively simple, low-cost, sensitive, and selective without using any sophisticated instruments, therefore it may have a promising prospect for detecting targets in clinical medicine, food safety analysis, and environmental monitoring.
College of Chemistry, Fuzhou University, Fuzhou, Fujian 350116, China.
Cuiying
C
Lin
College of Chemistry, Fuzhou University, Fuzhou, Fujian 350116, China.
Yajuan
Y
Guo
College of Chemistry, Fuzhou University, Fuzhou, Fujian 350116, China.
Mengmeng
M
Zhao
College of Chemistry, Fuzhou University, Fuzhou, Fujian 350116, China.
Mi
M
Sun
College of Biological Science and Technology, Fuzhou University, Fuzhou, Fujian 350116, China. Electronic address: luofang0812@163.com.
Fang
F
Luo
College of Chemistry, Fuzhou University, Fuzhou, Fujian 350116, China.
Longhua
L
Guo
College of Chemistry, Fuzhou University, Fuzhou, Fujian 350116, China.
Bin
B
Qiu
College of Chemistry, Fuzhou University, Fuzhou, Fujian 350116, China.
Zhenyu
Z
Lin
College of Chemistry, Fuzhou University, Fuzhou, Fujian 350116, China.
Guonan
G
Chen
D015374:Biosensing Techniques / Q000379:methods*; D002214:Capsules; D003124:Colorimetry / Q000379:methods*; D006735:Horseradish Peroxidase / Q000737:chemistry* / Q000378:metabolism; D006801:Humans; D007118:Immunoassay / Q000379:methods*; D053124:Influenza A Virus, H5N1 Subtype / Q000302:isolation & purification*; D057230:Limit of Detection; D008081:Liposomes / Q000737:chemistry*
D002214:Capsules; D008081:Liposomes; D006735:Horseradish Peroxidase
Colorimetric; H5N1; Immunoassay; Liposome; Signal amplification