Ultrasensitive optical DNA biosensor based on surface immobilization of molecular beacon by a bridge structure.
A novel biotinylated molecular beacon (MB) probe was developed to prepare a DNA biosensor using a bridge structure. MB was biotinylated at the quencher side of the stem and linked on a biotinylated glass cover slip through streptavidin, which acted as a bridge between MB and glass matrix. An efficient fluorescence microscope system was constructed to detect the fluorescence change caused by the conformation change of MB in the presence of complementary DNA target. The proposed biosensor was used to directly detect, in real-time, the target DNA molecules. The bridge immobilization method caused the proposed DNA biosensor to have a faster and more stable response. Under the optimal conditions, the newly developed DNA biosensor showed a linear response toward ssDNA in the range of 5-100 nM with a detection limit of 2 nM. It was interesting to note that the described biosensor was reproducible after being regenerated by urea.
Li
J
J
Institute of Biotechnology and Biomedical Engineering, College of Chemistry & Chemical Engineering, Hunan University, Changsha, P R China.
Tan
W
W
Wang
K
K
Xiao
D
D
Yang
X
X
He
X
X
Tang
Z
Z
D015374:Biosensing Techniques / Q000379:methods*; D001710:Biotin / Q000737:chemistry; D015342:DNA Probes / Q000737:chemistry*; D005336:Fiber Optic Technology / Q000379:methods*; D005456:Fluorescent Dyes / Q000737:chemistry* / Q000378:metabolism; D015394:Molecular Structure; D015345:Oligonucleotide Probes / Q000737:chemistry*; D012235:Rhodamines / Q000737:chemistry; D012680:Sensitivity and Specificity; D019809:Streptavidin / Q000737:chemistry; D013499:Surface Properties; D004124:p-Dimethylaminoazobenzene / Q000031:analogs & derivatives* / Q000737:chemistry
D015342:DNA Probes; D005456:Fluorescent Dyes; D015345:Oligonucleotide Probes; D012235:Rhodamines; C005358:tetramethylrhodamine; C063127:4-(4-dimethylaminophenylazo)benzoic acid; D001710:Biotin; D019809:Streptavidin; D004124:p-Dimethylaminoazobenzene