Detection of thrombin using electrogenerated chemiluminescence based on Ru(bpy)3(2+)-doped silica nanoparticle aptasensor via target protein-induced strand displacement.
A sensitive and selective aptasensor using tri(2,2'-bipyridyl)ruthenium(II)-doped silica nanoparticles (Ru(bpy)3(2+)-doped SNPs) as DNA tags for detection of thrombin is developed based on the target protein-induced strand displacement of the DNA probe. For the proposed aptasensor, the aptamer was assembled on the surface of the Au electrode through Au-S binding. The hybridization event between the DNA probe labeled by the Ru(bpy)3(2+)-doped SNPs and the aptamer was evaluated by electrogenerated chemiluminescence (ECL) measurements. Then, the DNA probe was displaced by thrombin and the binding event between the thrombin and the aptamer was monitored by ECL measurements again. The difference of ECL intensity (deltaI(ECL)) of the two events could be used to quantify the thrombin. Other proteins, such as bovine serum albumin and bovine hemoglobin, had almost negligible deltaI(ECL). Under the optimal conditions, the deltaI(ECL) was linearly related to the concentration of the thrombin in the range of 10 fM to 10 pM and the detection limit was down to 1.0 fM since SNPs containing a large number of Ru(bpy)3(2+) molecules were labeled on the DNA probe.
Wang
Xiaoying
X
Department of Chemistry, East China Normal University, Shanghai 200062, PR China.
Zhou
Jingming
J
Yun
Wen
W
Xiao
Shasha
S
Chang
Zhu
Z
He
Pingang
P
Fang
Yuzhi
Y
D015082:2,2'-Dipyridyl / Q000031:analogs & derivatives* / Q000737:chemistry; D000818:Animals; D002417:Cattle; D056831:Coordination Complexes; D015342:DNA Probes / Q000737:chemistry*; D006801:Humans; D007202:Indicators and Reagents / Q000737:chemistry; D049449:Luminescence; D053758:Nanoparticles / Q000737:chemistry*; D011506:Proteins / Q000737:chemistry*; D012680:Sensitivity and Specificity; D012822:Silicon Dioxide / Q000737:chemistry*; D013917:Thrombin / Q000032:analysis*; D017975:Ruthenium Compounds
D015082:2,2'-Dipyridyl; D056831:Coordination Complexes; D015342:DNA Probes; D007202:Indicators and Reagents; D011506:Proteins; D012822:Silicon Dioxide; D013917:Thrombin; C547232:tris(2,2-bipyridine)-ruthenium(II); D017975:Ruthenium Compounds