Electrogenerated chemiluminescence detection of adenosine based on triplex DNA biosensor.
A novel electrogenerated chemiluminescence (ECL) biosensor based on the construction of triplex DNA for the detection of adenosine was designed. The ECL biosensor employs an aptamer as a molecular recognition element, and quenches ECL of tris(2,2'-bipyridine) ruthenium (Ru(bpy)(3)(2+)) by ferrocenemonocarboxylic acid (FcA). Through self-assembly technology, the ECL probe of thiolated hairpin adenosine aptamer tagged was self-assembled onto the surface of a gold electrode with an ECL signal producer Ru(bpy)(3)(2+) derivative (Ru-DNA-1). The adenosine aptamer, including a section of triplex characteristic chain, formatted triplex DNA with two other DNAs (DNA-2, Fc-DNA-3) in the presence of triplex DNA binder coralyne chloride (CORA). Fc-DNA-3 was tagged with an ECL quencher ferrocenemonocarboxylic acid (FcA), a quenching probe. In the presence of adenosine, the aptamer sequence (Ru-DNA-1) prefers to form the aptamer-adenosine complex with hairpin configuration and the switch of the DNA-1 occurs in conjunction with the generation of a strong ECL signal owing to the dissociation of a quenching probe. Meanwhile, a control experiment was performed; the ECL-duplex biosensor was designed to detect adenosine. The detection limits were 2.7×10(-10) mol L(-1) and 2.3×10(-9) mol L(-1) for the ECL-triplex DNA biosensor and ECL-duplex DNA biosensor, respectively, which demonstrated that the ECL-triplex DNA biosensor improved the sensitivity and specificity greatly.
Ye
Sujuan
S
State Key Laboratory Base of Eco-chemical Engineering, College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao 266042, PR China.
Li
Hongxia
H
Cao
Wei
W
D000241:Adenosine / Q000032:analysis* / Q000737:chemistry; D015374:Biosensing Techniques / Q000295:instrumentation*; D003217:Conductometry / Q000295:instrumentation*; D004247:DNA / Q000737:chemistry*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D008163:Luminescent Measurements / Q000295:instrumentation*
C051802:triplex DNA; D004247:DNA; D000241:Adenosine