A fluorescence biosensor for VEGF detection based on DNA assembly structure switching and isothermal amplification.
Vascular endothelial growth factor (VEGF) is an important biomarker in cancer angiogenesis. Here, we develop a aptasensor method for VEGF detection based on DNA assembly structure switching and isothermal amplification. The design employs a DNA assembly made of a isothermal amplification template, a aptamer, a primer and a protector chain. The DNA assembly is unable to undergo isothermal amplification in the absence of target. The presence of the target, however, triggers a structure switching event that causes hybridization of primer with template to facilitate isothermal amplification. Whereafter, toehold-mediated DNA strand displacement reaction between the generated (single-stranded DNA) ssDNA and fluorescent/quencher labeled probe are performed. Then, the increase in fluorescence provides an analytical signal. This strategy opens up a sensitive, selective and simple sensing platform for detection of VEGF. The system was also implemented to analyze the VEGF in human serum samples with satisfactory results.
Key Laboratory of Laboratory Medical Diagnostics, Ministry of Education, Department of Laboratory Medicine, Chongqing Medical University, Chongqing 400016, PR China.
Junlong
J
Li
Key Laboratory of Laboratory Medical Diagnostics, Ministry of Education, Department of Laboratory Medicine, Chongqing Medical University, Chongqing 400016, PR China.
Kexin
K
Sun
Department of Clinical Laboratory, Chongqing Municipal Jiulongpo District the First People's Hospital, Chongqing 400050, PR China.
Zhongping
Z
Chen
Institute of Medical Technology, Baotou Medical College, Baotou 014060, PR China.
Jifei
J
Shi
Clinical Laboratory, The First Affiliated Hospital, Chongqing Medical University, Chongqing 400016, PR China.
Dandan
D
Zhou
Key Laboratory of Laboratory Medical Diagnostics, Ministry of Education, Department of Laboratory Medicine, Chongqing Medical University, Chongqing 400016, PR China. Electronic address: guomingxie@cqmu.edu.cn.
Guoming
G
Xie
D015374:Biosensing Techniques; D004277:DNA, Single-Stranded / Q000737:chemistry; D005453:Fluorescence; D054856:G-Quadruplexes; D006801:Humans; D057230:Limit of Detection; D021141:Nucleic Acid Amplification Techniques; D042461:Vascular Endothelial Growth Factor A / Q000737:chemistry / Q000302:isolation & purification*
D004277:DNA, Single-Stranded; C467484:VEGFA protein, human; D042461:Vascular Endothelial Growth Factor A
Aptamer; Fluorescence biosensor; Isothermal amplification; Vascular endothelial growth factor (VEGF)