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Updated: Jun 3, 2026
Phthalic Acid Ester-Binding DNA Aptamer Selection, Characterization, and Application to an Electrochemical Aptasensor
Published on: March 21, 2018
A simple assay to amplify the electrochemical signal by the aptamer based biosensor modified with CdS hollow
Yanfen Li1, Jianchun Bao, Min Han
1Jiangsu Key Laboratory of Biofunctional Materials, Laboratory of Electrochemistry, College of Chemistry and Materials Science, Nanjing Normal University, Nanjing 210097, PR China.
Abstract:
A simple method to amplify the electrochemical signal by an aptamer with 22 bases modified with CdS hollow nanospheres (CdSHNs) was described. Using the thrombin as a model, the interaction between the aptamer and CdSHNs was characterized by cyclic voltammetry, electrochemical impedance spectroscopy and circular dichroism spectroscopy. CdSHNs promoted the electron transfer between the gold electrode and K(3)[Fe(CN)(6)] and facilitated the conformation conversion of the aptamer from hairpin to G-quadruplex after the aptamer interacted with thrombin. Under optimal conditions, the modified electrode could be used for the determination of thrombin from 0 to 33 μg mL(-1) and the sensitivity was 1.34 μA mL μg(-1)cm(-2), while the linear range of the modified electrode without the immobilization of CdSHNs was from 2.75 to 27.5 μg mL(-1) and the sensitivity was 0.062 μA mL μg(-1)cm(-2). This constructed biosensor also had a good stability, specificity, reproducibility and accuracy which could provide a promising platform for fabrication of aptamer based biosensors.
