Open AccessColorimetric assay for tetracyclines based on europium ion-induced aggregation of gold nanoparticles
Author(s) -
Peihua Wang,
Ningning Yue,
Chang Liu,
Aiping Fan
Publication year - 2022
Publication title -
analytical sciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.392
H-Index - 73
eISSN - 1348-2246
pISSN - 0910-6340
DOI - 10.1007/s44211-022-00136-0
Subject(s) - chemistry , surface plasmon resonance , europium , colloidal gold , nanoparticle , sodium borohydride , ion , nuclear chemistry , aptamer , absorption (acoustics) , nanotechnology , organic chemistry , materials science , physics , biology , acoustics , genetics , catalysis
Oxytetracycline-capped gold nanoparticles (OTC-Au NPs) were prepared using sodium borohydride as the reductant and OTC as the capping agent, respectively. The prepared OTC-Au NPs with a size of 6 nm have a maximum surface plasma resonance (SPR) absorption located at 514 nm. The OTC on the surface of Au NPs still can coordinate with Eu 3+ ions. Due to the property that OTC has multivalent binding sites with Eu 3+ ions, Eu 3+ ions can induce the aggregation of OTC-Au NPs. Based on the Eu 3+ ions-aggregated OTC-Au NPs, a simple aptamer-free colorimetric sensing method for TCs was developed. Briefly, free TCs compete with OTC on the surface of Au NPs resulting in the change of OTC-Au NPs from an aggregation state to a dispersed state. The whole process takes only 5 min, and as low as 20 nM OTC, 14 nM tetracycline (TC), and 20 nM doxycycline (DC) could be sensitively detected, respectively. The proposed method was also featured as good repeatability and specificity, and was applied to the detection of OTC in lake water with satisfactory recovery.