An electrochemical impedimetric platform formed by a CNT@UiO-66 nanocomposite for quantitative analysis of oxytetracycline

Functional materials are considered one of the most critical factors in constructing high-performance electrochemical aptasensors in the sensing field. In this work, the microporous Zr-MOF UiO-66 (UiO = Universitetet i Oslo) is selected for assembly with carbon nanotubes (CNTs) to prepare a CNT@UiO-66 composite. The as-synthesized CNT@UiO-66 composite has a high surface area, excellent stability, good electrical conductivity, and abundant Zr(iv) sites, conferring it great potential for application in fabricating high-performance electrochemical aptasensors. It is gratifying that this electrochemical impedimetric aptasensor can detect trace oxytetracycline (OTC) from 0.01 to 0.7 pg mL(-1) with a low limit of detection (LOD) of 1.48 fg mL(-1). Meanwhile, this fabricated sensor based on CNT@UiO-66 has fine stability, excellent selectivity, and available reproducibility. In particular, the CNT@UiO-66-based aptasensor can quantitatively detect the OTC concentration in real samples.

Automated summary

In this study, a CNT@UiO-66 composite was prepared by assembling the microporous Zr-MOF UiO-66 with carbon nanotubes (CNTs). The composite exhibited high surface area, excellent stability, good electrical conductivity, and abundant Zr(iv) sites, making it highly suitable for fabricating high-performance electrochemical aptasensors. The fabricated sensor based on CNT@UiO-66 showed fine stability, excellent selectivity, and reproducibility, and could quantitatively detect the concentration of oxytetracycline (OTC) in real samples.