Multifunctional CuS-CDs@MnO 2 nanoparticles and liposome-Assisted amplification for triple-mode detection of Enrofloxacin

Abstract

The residues of enrofloxacin (ENR) in animal-derived food and water environments have emerged as a growing public health concern in recent years. Herein, a tri-mode biosensor was designed by employing CuS-CDs@MnO2 as the signal probe and glutathione (GSH)-loaded liposomes for amplification. The manganese dioxide (MnO2) shell of the nanocomposite quenched the fluorescence of CuS-CDs, reduced its photothermal performance and also endowed it with the oxidase-like activity. In the presence of ENR, a large amount of GSH was released after aptamer recognition and magnetic separation. Then, the shell of CuS-CDs@MnO2 was destroyed, leading to change the fluorescence, colorimetric, and photothermal temperature signals. By integrating triple-mode signal output and liposomes amplification, this platform enabled specific and ultrasensitive detection procedure with the limits of detection reaching 0.543 ng/mL (FL response), 30.2 ng/mL (photothermal response) and 7.06 ng/mL (UV−vis response), respectively. Notably, the triple-mode output of the innovative platform could cross-validate mutually and improve analytical reliability. Moreover, this platform displayed satisfactory performance for the ENR detection in actual spiked samples, with recoveries ranging from 92.0 % to 108.9 %, demonstrating promising application prospects.