A Novel Aptamer Biosensor Based on a Localized Surface Plasmon Resonance Sensing Chip for High-Sensitivity and Rapid Enrofloxacin Detection

Abstract

Enrofloxacin, a fluoroquinolone widely used in animal husbandry, presents environmental and human health hazards due to its stability and incomplete hydrolysis leading to residue accumulation. To address this concern, a highly sensitive aptamer biosensor utilizing a localized surface plasmon resonance (LSPR) sensing chip and microfluidic technology was developed for rapid enrofloxacin residue detection. AuNPs were prepared by the seed method and the AuNPs-Apt complexes were immobilized on the chip by the sulfhydryl groups modified on the end of the aptamer. The properties and morphologies of the sensing chip and AuNPs-Apt complexes were characterized by Fourier transform infrared spectroscopy (FTIR), UV-Vis spectrophotometer, and scanning electron microscope (SEM), respectively. The sensing chip was able to detect enrofloxacin in the range of 0.01–100 ng/mL with good linearity, and the relationship between the response of the sensing chip and the concentration was Δλ (nm) = 1.288log ConENR (ng/mL) + 5.245 (R2 = 0.99), with the limit of detection being 0.001 ng/mL. The anti-interference, repeatability, and selectivity of this sensing chip were studied in detail. Compared with other sensors, this novel aptamer biosensor based on AuNPs-Apt complexes is expected to achieve simple, stable, and economical application in the field of enrofloxacin detection.

Gold Nanoparticle-Coated Magnetic Graphene Oxide as a Dual-Mode Immunochromatographic Biosensor for Enrofloxacin Residue Analysis in Food Samples

“…ENR monoclonal antibody host mouse clone number 7F21G1F7E8#1 was purchased from Thermo Fisher Scientific (Massachusetts, USA). The aptamer sequence (5′-Biotin-CCCATCAGGGGGCTAGGCTAA-CACGGTTCGGCTCTCTGAGCCCGGGTTATTTCAGGGGGA-3′) 50 used was commissioned to Shanghai Jerry Bioengineering Co., Ltd. (Shanghai, China). The other antibody, the host of the goatresistant mouse, was purchased from Beijing Zhongshan Jinqiao Biotechnology Co., Ltd. (Beijing, China).…”