A joint action of aptamers and gold nanoparticles chemically trapped on a glassy carbon support for the electrochemical sensing of ofloxacin

SENSORS AND ACTUATORS B-CHEMICAL

卷:240

Article

Pilehvar, Sanaz¹  Reinemann, Christine²  Bottari, Fabio¹  Vanderleyden, Els³  Van Vlierberghe, Sandra^1,3  Blust, Ronny⁴  Strehlitz, Beate²  De Wael, Karolien¹ 

[1] Univ Antwerp, Dept Chem, AXES Res Grp, Groenenborgerlaan 171, B-2020 Antwerp, Belgium

[2] UFZ Helmholtz Ctr Environm Res, Dept Environm & Biotechnol Ctr, Permoserstr 15, D-04318 Leipzig, Germany

[3] Univ Ghent, Polymer Chem & Biomat Res Grp, Krijgslaan 281, B-9000 Ghent, Belgium

[4] Univ Antwerp, Dept Biol, Sphere Res Grp, Groenenborgerlaan 171, B-2020 Antwerp, Belgium

关键词: Ofloxacin;    Au nanoparticles;    Electrochemical aptasensor;    Covalent attachment;    Water quality;    Environmental monitoring;   

DOI  :  10.1016/j.snb.2016.09.075

来源: Elsevier

【 摘 要 】

A joint action of ssDNA aptamers and electrochemistry is a key element in developing successful biosensing platforms, since aptamers are capable of binding various targets with high specificity, and electrochemistry is one of the most sensitive techniques for on-site detections. A continuous search for improved immobilization and sensing strategies of aptamers on transducer surfaces resulted in the strategy presented in this article. The strategy is based on the covalent attachment of gold nanoparticles on the surface of glassy carbon electrodes through sulfhydryl-terminated monolayer, acting as a glue to connect AuNPs on the electrode. The covalently attached gold nanoparticles modified glassy carbon electrodes have been applied for the efficient immobilization of thiolated ssDNA probes, with a surface coverage of about 8.54 x 10(13) molecules cm(-2) which was 7-fold higher than that on the electrochemically deposited gold nanoparticles. Consequently, improved sensitivity, good reproducibility and stability are achieved for electrochemical aptasensor. Combined with the high affinity and specificity of an aptamer, a simple, novel, rapid, sensitive and label-free electrochemical aptasensor was successfully fabricated for ofloxacin (OFL) detection. The linear dynamic range of the sensor varies between 5 x 10(-8) to 2 x 10(-5) M OFL with a detection limit of 1 x 10(-9) M OFL. A potential application in environmental monitoring was demonstrated by using this sensing strategy for the determination of OFL in (experimentally spiked) real samples such as tap water and effluent of sewage treatment plant. The proposed nanoaptasensor combines the advantages of the covalent attachment of neatly arranged AuNPs (enlarged active surface area and strengthened electrochemical signal) and the elimination of labels for the amplified detection of OFL, with the covalent attachment of highly specific aptamers to the surface of the modified electrode. (C) 2016 Elsevier B.V. All rights reserved.

【 授权许可】

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