Ratiometric electrochemical aptasensor based on ferrocene and carbon nanofibers for highly specific detection of tetracycline residues

Qingcui Xu,Jiayun Fu,Zengning Liu,Yemin Guo,Xia Sun,Wenping Zhao,Haiyun Zhang

doi:10.1038/s41598-017-15333-5

Qingcui Xu, Jiayun Fu + Show 5 more

Open Access

https://doi.org/10.1038/s41598-017-15333-5

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Journal: Scientific Reports	Publication Date: Nov 7, 2017
Citations: 28	License type: open-access

Affiliation: Shandong University of Technology

Abstract

A sensitive and efficient ratiometric electrochemical aptasensor was designed for tetracycline (TET) detection in milk. The ratiometric electrochemical aptasensor was constructed by integrating two aptasensors termed as aptasensor 1 and aptasensor 2. The aptasensor 1 was fabricated that based on ferrocene (Fc) and gold nanoparticles (AuNPs) nanocomposite. Meanwhile, the aptasensor 2 was prepared that based on carbon nanofibers (CNFs) and AuNPs nanocomposite. TET-aptamer was immobilized effectively onto screen-printed carbon electrodes (SPCEs) surface through forming Au-S bond between AuNPs and thiol of aptamer at 5′ end to construct the aptasensor 1 and aptasensor 2. And their detection results were calculated by ratio. Thus, the proposed ratiometric aptasensor solved the problem of low accuracy and large differences between batches. Under the optimized conditions, the TET was detected by differential pulse voltammetry (DPV). Taken advantage of ratio calculation, the as-prepared ratiometric aptasensor could detect TET quantitatively in the range of 10−8–10−3gL−1, with a detection limit of 3.3 × 10−7gL−1. Moreover, its applicability to TET-contaminated real samples (milk) showed an excellent agreement with the values determined by ultrahigh-performance liquid chromatography-tandem mass spectrometry (UPLC-ESI-MS/MS). With high sensitivity, accuracy and reliability, the developed ratiometric aptasensor held a great potential in TET detection for food safety.

Highlights

Tetracycline (TET) antibiotic, a kind of broad spectrum antibiotics, is used for prevention and treatment of animal diseases in livestock and poultry industry, and for promoting growth[1]
In an effort to protect consumers, a number of analytical methods have been developed to monitor antibiotic residues in milk. Some methods such as high performance liquid chromatography (HPLC)[3,4,5], LC coupled with tandem mass spectrometry (LC-MS/MS) and immunoassays[6] have been commonly performed for antibiotic residues detection
When Fc was coated by the aptamer, the electrochemical activity of the electrode surface was reduced and there is decreasing in the oxidation peak current

Summary

Introduction

Tetracycline (TET) antibiotic, a kind of broad spectrum antibiotics, is used for prevention and treatment of animal diseases in livestock and poultry industry, and for promoting growth[1]. The use of antibiotics, especially used without following label directions, can result in drug residues in animal-origin foods such as milk. Some methods such as high performance liquid chromatography (HPLC)[3,4,5], LC coupled with tandem mass spectrometry (LC-MS/MS) and immunoassays[6] have been commonly performed for antibiotic residues detection. Despite their accuracy and reliability, these methods have certain practical disadvantages such as complexity, high cost, and time consumption. Biosensors detection methods can substitute the www.nature.com/scientificreports/

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