An aptamer embedded in a molecularly imprinted polymer for impedimetric determination of tetracycline
The authors introduce a new kind of aptameric imprinted polymer for sensing tetracycline (TET), thereby combining the unique features of aptamer-based and molecularly imprinted polymer based recognition. The dual recognition scheme results in sensing capabilities that are superior to those of the aptamer alone, or of a conventional molecularly imprinted polymer alone. In the first step, the aptamer-TET complex was immobilized on the surface of a glassy carbon electrode (GCE) decorated with gold nanoparticles. Dopamine was then electropolymerized on the surface of the modified GCE to entrap the aptamer-TET complex. TET was then extracted with an ethanol-acetic acid mixture (95:5) in order to create void cavities. On exposure to TET, the cavities are filled with TET again, and this leads to a retardment of the interfacial charge transfer of the redox probe hexacyanoferrate, typically measured at a peak voltage of 0.22 V vs. Ag/AgCl. The assay detects TET in the concentration ranges from 0.5–100 pM and from 1–1000 nM with a very low limit of detection of 144 fM. Its superior selectivity and affinity make this assay a viable tool as demonstrated for the successful analysis of TET in spiked milk samples.
KeywordsMolecular imprinted polymer Milk Nanohybrid sensor Dual recognition
The authors gratefully acknowledge the support of this work by the Khorramabad Branch, Islamic Azad University for financial support.
Compliance with ethical standards
The author(s) declare that they have no competing interests.
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