Fabricating UCNPs-AuNPs Fluorescent Probe for Sensitive Sensing Thiamphenicol

A novel fluorescent probe has been constructed based on fluorescence resonance energy transfer(FRET) between upconversion nanomaterials(UCNPs) NaYF 4 :Yb,Er and gold nanoparticles(AuNPs). The fluorescent “off-on” switching was formed for the detection of thiamphenicol(TAP) in egg samples. The fluorescence of UCNPs can be quenched to a certain degree by AuNPs. After adding TAP, the AuNPs generated aggregation and the fluorescence of UCNPs was recovered. The synthesized amination UCNPs and AuNPs were characterized by Fourier transform infrared spectroscopy(FTIR), UV-Vis, X-ray diffraction(XRD), energy dispersive spectrometer(EDS), and transmission electron microscope(TEM) techniques for observation and confirmation. As a model target, the detection of TAP has two linear ranges in the buffer solution within 0.01–0.1 µmol/L and 0.1–1 µmol/L using this fluorescent probe. The detection limit was obtained to be 0.003 µmol/L( S/N =3), which is favorable for trace analysis. The recovery of TAP from 98.2% to 105.3% was obtained, and the relative standard deviation(RSD) was from 2.5% to 4.3%. Furthermore, the method established in this study based on the UCNPs auto-low background fluorescence has high selectivity and strong ability to eliminate interference, which is beneficial to analyzing complex samples.