Dual-Channel Probe of Carbon Dots Cooperating with Lanthanide Complex Employed for Simultaneously Distinguishing and Sequentially Detecting Tetracycline and Oxytetracycline.

Jun Xu,Xiangzhen Chen,Rujie Chen,Lei Jia,Zhitao Xu

doi:10.3390/nano12010128

Abstract

Tetracycline (TC) and oxytetracycline (OTC) are the most widely used broad-spectrum antimicrobial agents in tetracycline drugs, and their structures and properties are very similar, so it is a great challenge to distinguish and detect these two antibiotics with a single probe at the same time. Herein, a dual-channel fluorescence probe (SiCDs@mMIPs-cit-Eu) was developed by integrating two independent reaction sites with SiCDs-doped mesoporous silica molecular imprinting group and europium complex group into a nanomaterial. The synergistic influence of inner filter effect and “antenna effect” can be guaranteed to solve the distinction between TC and OTC. Moreover, this novel strategy can also sequentially detect TC and OTC in buffer solution and real samples with high sensitivity and selectivity. This method revealed good responses to TC and OTC ranging from 0 to 5.5 μM with a detection limit of 5 and 16 nM, respectively. Combined with the smartphone color-scanning application, the portable and cheap paper-based sensor was designed to realize the multi-color visual on-site detection of TC and OTC. In addition, the logic gate device was constructed according to the fluorescence color change of the probe for TC and OTC, which provided the application possibility for the intelligent detection of the probe.

Highlights

Antibiotics have helped humans conquer many diseases caused by bacteria, more than 10% of people are suffering from the side effects of antibiotics [8]
We described a novel discrimination strategy for TC and OTC based on two potential recognition sites of a europium functionalized organosilane-functionalized carbon dots (SiCDs) doped mesoporous silica molecularly imprinted probe (Scheme 1)
The SiCDs were synthesized by the previously reported procedures include the thermal decomposition of anhydrous citric acid and passivation of amino group in silane coupling agent with carboxyl group in cit, which was further confirmed by FTIR analysis

Summary

Introduction

Tetracyclines (TCs) are a widely used tetracycline antibiotic, which are often used to treat human and animal infections caused by both Gram-positive and Gram-negative bacteria [1,2]. Because of their remarkable antibacterial effect, TCs are often used as a feed additive to prevent and treat diseases and promote the growth and development of animals in the process of animal breeding [3]. The unreasonable use of TCs, including tetracycline (TC) and oxytetracycline (OTC), may lead to their accumulation in the human body because of the residues in animal derived foods, such as milk, eggs, meat, and honey [4,5,6,7]. Antibiotics have helped humans conquer many diseases caused by bacteria, more than 10% of people are suffering from the side effects of antibiotics [8]

Methods

Results

Conclusion