ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

A fluorescent aptasensor based on fluorescence resonance energy transfer for the detection of ofloxacin

Wei-Chuang Kong, Miao-Miao Wu, Chen-Chen Li, Jiang-Nan Wang, Ya-Li Meng, Xiao-Juan Jia, Zhen-Hui Xin, and Yan-Fei Kang

College of Laboratory Medicine, Institute of Pathogen Biology and Immunology, Hebei Key Laboratory of Neuropharmacology, Hebei Key Laboratory of Quality and Safety Analysis-Testing for Agro-Products and Food and Zhang Jiakou Key Laboratory of Organic Light Functional Materials, Hebei North University, Zhangjiakou, China

E-mail: 331747894@qq.com

Received: 27 August 2024  Accepted: 22 March 2025

Abstract:

Ofloxacin (OFL), as third-generation fluoroquinolone antibiotics, is commonly used to treat bacterial infections in humans and animals. However, excessive use of OFL has led to significant environmental contamination, raising concerns about food safety and public health. The current detection methods for OFL residues often come with lengthy detection times and narrow detection ranges. In this context, we developed a fluorescence aptasensor based on FRET (Förster Resonance Energy Transfer) between the FAM fluorescent group and gold nanoparticles (AuNPs), offering a more rapid and a wide detection range, as well as achieving the detection of OFL in multiple practical samples. The nucleic acid aptamer labeled with FAM (FAM-Apt) binds with the AuNPs to quench FAM fluorescence due to FRET. Upon addition of OFL, it preferentially binds to aptamers, leading to an increase in the fluorescence intensity of FAM-Apt. Therefore, this strategy provided the possibility for OFL detection. The results show that this sensor was able to selectively detect OFL with a linear range of 0–1500 nM. The limit of detection was 4.84 nM under optimized conditions. The aptasensor successfully detected OFL in serum, urine, tap water, river water, pork, chicken and milk, with spiked recoveries ranging from 98.00 to 102.56% and relative standard deviations ranging from 0.41 to 6.99%, demonstrating its potential for food safety applications. Overall, this research offers a wide detection range, faster, and more affordable method for OFL detection in practical samples.

Keywords: Biological Fluorescence; Fluorescent Probes; Fluorescence Spectroscopy; Fluorescence Resonance Energy Transfer; Fluorescent dyes; Fluorescent proteins; Ofloxacin; FAM-aptamer; Gold nanoparticles; Fluorescence resonance energy transfer

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-025-04032-5

Chemical Papers 79 (6) 3799–3810 (2025)