Terminal protection of a small molecule-linked loop DNA probe for turn-on label-free fluorescence detection of proteins.
A novel label-free turn-on fluorescence biosensor for the determination of streptavidin (SA) was proposed. Using terminal protection of small molecule-linked DNA chimeras, which can protect DNA from degradation by various exonucleases when the small molecule moieties are bound to their protein target, we designed a loop probe, where the 3'-end was modified with biotin to resist digestion by exonucleases in the presence of target SA. Coupled with an intercalating dye, SYBR Green I, strong enhancement of the fluorescence signals was obtained compared with that in the absence of SA. A linear correlation equation was obtained for SA from 0 to 200nM with a limit detection of 0.4nM. This strategy holds great promise for practical applications with good specificity and sensitivity.
Department of Chemistry and the MOE Key Laboratory of Spectrochemical Analysis & Instrumentation, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China.
Xuexu
X
Chen
School of Physics and Centre for Climate and Air Pollution Studies, Ryan Institute, National University of Ireland Galway, University Road, Galway, Ireland.
Chunshui
C
Lin
Department of Chemistry and the MOE Key Laboratory of Spectrochemical Analysis & Instrumentation, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China.
Yiying
Y
Chen
Fujian Research Institute of Metric Science, Fuzhou 350003, China.
Feng
F
Luo
Department of Chemistry and the MOE Key Laboratory of Spectrochemical Analysis & Instrumentation, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China. Electronic address: yrwang@xmu.edu.cn.
Yiru
Y
Wang
Department of Chemistry and the MOE Key Laboratory of Spectrochemical Analysis & Instrumentation, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China; State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen 361005, China. Electronic address: xichen@xmu.edu.cn.
Xi
X
Chen
D052160:Benzothiazoles; D015374:Biosensing Techniques / Q000379:methods*; D001710:Biotin / Q000737:chemistry; D015342:DNA Probes / Q000737:chemistry*; D003959:Diamines; D005090:Exodeoxyribonucleases / Q000737:chemistry; D005453:Fluorescence; D005456:Fluorescent Dyes / Q000737:chemistry; D057230:Limit of Detection; D009930:Organic Chemicals / Q000737:chemistry; D011804:Quinolines; D013050:Spectrometry, Fluorescence / Q000379:methods; D019809:Streptavidin / Q000032:analysis*
D052160:Benzothiazoles; D015342:DNA Probes; D003959:Diamines; D005456:Fluorescent Dyes; D009930:Organic Chemicals; D011804:Quinolines; C098022:SYBR Green I; D001710:Biotin; D019809:Streptavidin; D005090:Exodeoxyribonucleases; C028450:exodeoxyribonuclease I; C020133:exodeoxyribonuclease III
Exonucleases; Fluorescence; Streptavidin-biotin