Electrochemical detection of thrombin by sandwich approach using antibody and aptamer.
The goal of this work was to introduce a modified electrochemical sandwich model for target protein detection, exploiting antibody as the capturing probe, aptamer as the detection probe and methylene blue as the electrochemical active marker intercalating in the probing aptamer without previous labeling. With appropriate design of the sequence of the aptamer, the aptamer was successfully utilized instead of antibody for obtaining the electrochemical detection. A special immobilization interface consisting of nanogold-chitosan composite film was used to improve the conductivity and performance characteristics of the electrode. The capturing antibody was linked to the glassy carbon electrodes modified with composite film via a linker of glutaraldehyde. Differential pulse voltammetry was performed to produce the response signal. Thrombin was taken as the model target analyte to demonstrate the feasibility of proposed methodology. The sensor shows the linear response for thrombin in the range 1-60 nM with a detection limit of 0.5 nM. The proposed approach provides an alternative approach for sandwich protein assay using aptamers.
State Key Laboratory for Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, PR China.
Yan
Y
Kang
Ke-Jun
KJ
Feng
Ji-Wei
JW
Chen
Jian-Hui
JH
Jiang
Guo-Li
GL
Shen
Ru-Qin
RQ
Yu
D000906:Antibodies / Q000276:immunology*; D052157:Aptamers, Nucleotide / Q000737:chemistry* / Q000235:genetics; D002244:Carbon / Q000737:chemistry; D048271:Chitosan / Q000737:chemistry; D004563:Electrochemistry; D004566:Electrodes; D005898:Glass; D006046:Gold / Q000737:chemistry; D006801:Humans; D008855:Microscopy, Electron, Scanning; D049329:Nanostructures / Q000737:chemistry; D009994:Osmolar Concentration; D013917:Thrombin / Q000032:analysis* / Q000737:chemistry* / Q000235:genetics / Q000276:immunology
D000906:Antibodies; D052157:Aptamers, Nucleotide; D002244:Carbon; D006046:Gold; D048271:Chitosan; D013917:Thrombin