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Updated: Dec 31, 2025
Design and Development of Aptamer–Gold Nanoparticle Based Colorimetric Assays for In-the-field Applications
Published on: June 23, 2016
Fluorometric determination of lead(II) by using aptamer-functionalized upconversion nanoparticles and
Min Chen1, Mehedi Hassan1, Huanhuan Li2
1School of Food and Biological Engineering Jiangsu University, Xuefu Road 301, Zhenjiang, 212013, People's Republic of China.
Abstract:
A fluorescent nanoprobe for Pb(II) has been developed by employing aptamer-functionalized upconversion nanoparticles (UCNPs) and magnetic Fe3O4-modified (MNPs) gold nanoparticles (GNPs). First, aptamer-functionalized UCNPs and aptamer-functionalized magnetic GNPs were synthesized to obtained the fluorescent nanoprobe. The particles were combined by adding a complementary ssDNA. In the absence of Pb(II), the UCNPs, MNPs and GNPs are linked via complementary base pairing. This led to a decrease in the green upconversion fluorescence peaking at 547 nm (under 980 nm excitation). In the presence of Pb(II), the dsDNA between UCNPs and MNPs-GNPs is cleaved, and fluorescence recovers. This effect allows Pb(II) to be quantified, with a wide working range of 25-1400 nM and a lower detection limit of 5.7 nM. The nanoprobe gave satisfactory results when analyzing Pb(II) in tea and waste water. Graphical abstractSchematic representation of fluorescent nanoprobe based on fluorescence resonance energy transfer (FRET) between upconversion nanoparticles (UCNPs) and gold nanoparticles (GNPs)-Fe3O4 magnetic nanoparticles (MNPs) for detection of Pb2+.
