A sensitive nanoporous gold-based electrochemical aptasensor for thrombin detection.
An attempt was made in the present paper to develop a nanoporous gold (NPG)-based electrochemical aptasensor for thrombin detection. The substrate electrode NPG was in situ fabricated by a facile one-step square wave potential pulse (SWPP) treatment. The treatment involved repeated gold oxidation-reduction and intensive H(2) bubbles evolution. After 100min treatment, the active surface area of Au increased greatly (34 times). The electrochemical aptasensor was fabricated using a layer-by-layer assembling strategy. A "sandwich" structure was formed via thrombin connecting the aptamer-modified NPG and the aptamer-modified Au nanoparticles (AuNPs). The AuNPs was modified with two kinds of single strand DNA (ssDNA). One was aptamer of thrombin, but the other was not, reducing the cross-reaction between thrombin and its aptamer on the same AuNP. The electrochemical signal produced by the [Ru(NH(3))(6)](3+) bound to ssDNA via electrostatic interaction was measured by chronocoulometry. Due to the amplification effects of both NPG and AuNPs, this novel NPG-based aptasensor could detect thrombin quantitatively in the range of 0.01-22nM with a detection limit as low as 30fM. The present aptasensor also exhibited excellent selectivity, stability and reusability.
Qiu
Huajun
H
Key Laboratory of Colloid and Interface Chemistry of the Ministry of Education of China, Shandong University, Jinan 250100, PR China.
Sun
Yanli
Y
Huang
Xirong
X
Qu
Yinbo
Y
D052157:Aptamers, Nucleotide / Q000737:chemistry / Q000235:genetics; D001483:Base Sequence; D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods*; D004277:DNA, Single-Stranded / Q000737:chemistry / Q000235:genetics; D055664:Electrochemical Techniques / Q000295:instrumentation / Q000379:methods; D004566:Electrodes; D006046:Gold / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D008855:Microscopy, Electron, Scanning; D008956:Models, Chemical; D009154:Mutation; D016062:Porosity; D013917:Thrombin / Q000032:analysis* / Q000737:chemistry / Q000235:genetics
D052157:Aptamers, Nucleotide; D004277:DNA, Single-Stranded; D006046:Gold; D013917:Thrombin