Solid-phase hybridization efficiency improvement on the magnetic nanoparticle surface by using dextran as molecular arms.
For reducing the steric hindrance and nonspecific binding of the target DNA, the dextran was used as molecular arms to be immobilized on the surface of magnetic nanoparticles (MNPs). Magnetic separation was used in preparation of dextran-MNPs (DMNPs). Aspartic acid and aminated DNA probe were successively modified on the dextran immobilized on the surface of MNPs. These probe-DMNPs were successfully applied to detect biotin-labeled PCR product of E. coli O157:H7 genome by hybridization. Then the complexes were bonded with streptavidin-modified alkaline phosphatase (ALP-SA). Finally the chemiluminescent signals were detected by adding 3-(2-spiroadamantane)-4-methoxy-4- (3-phosphoryloxy) phenyl-1,2-dioxetane (AMPPD). The results showed that this method had a good specificity, and higher sensitivity than that when only MNPs were used as solid carriers.
State Key Laboratory of Bioelectronics, Southeast University, Nanjing 210096, China. lizhiyangcn@qq.com
Zhiyang
Z
Li
Haowen
H
Yang
Nongyue
N
He
Wenbiao
W
Liang
Chao
C
Ma
Muhammad Ali A
MA
Shah
Yongjun
Y
Tang
Song
S
Li
Hongna
H
Liu
Hesheng
H
Jiang
Yafen
Y
Guo
D015342:DNA Probes / Q000737:chemistry* / Q000648:ultrastructure*; D003911:Dextrans / Q000737:chemistry*; D058185:Magnetite Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure*; D008422:Materials Testing; D053769:Nanocapsules / Q000737:chemistry* / Q000648:ultrastructure*; D010316:Particle Size; D044367:Phase Transition; D013499:Surface Properties
D015342:DNA Probes; D003911:Dextrans; D058185:Magnetite Nanoparticles; D053769:Nanocapsules