A fluorescent aptasensor for Pb 2+ detection based on gold nanoflowers and RecJf exonuclease-induced signal amplification

A fluorescent aptasensor was constructed to detect lead ion (Pb ). Complementary DNA with sulfhydryl group (SH-cDNA) were loaded on gold nanoflowers materials (Au NFs) through Au-S bonds. Then, based on complementary base pairing between FAM modified Pb aptamer (FAM-Apt) and Au NFs/SH-cDNA system, a...

Full description

Saved in:
Bibliographic Details
Published in:Analytica chimica acta 2022-02, Vol.1192, p.339329
Main Authors: Liu, Ruike, He, Baoshan, Jin, Huali, Suo, Zhiguang
Format: Article
Language:English
Subjects:
Aptamers, Nucleotide
Exonucleases
Fluorescent Dyes
Gold
Lead
Reproducibility of Results
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:A fluorescent aptasensor was constructed to detect lead ion (Pb ). Complementary DNA with sulfhydryl group (SH-cDNA) were loaded on gold nanoflowers materials (Au NFs) through Au-S bonds. Then, based on complementary base pairing between FAM modified Pb aptamer (FAM-Apt) and Au NFs/SH-cDNA system, an Au NFs/SH-cDNA/FAM-Apt aptasensor was constructed. The fluorescence of FAM was quenched by Au NFs due to the fluorescence resonance energy transfer (FRET). Upon addition of Pb and RecJf exonuclease (RecJf Exo) for 1.5 h, the Apt changed to a G-quadruplex structure due to the high affinity between Pb and its aptamer, which lead to a large recovery in the fluorescence intensity. Under the optimized conditions, the presented aptasensor revealed high selectivity toward Pb in the concentration range of 0.5 nM-1 μM, with a limit of detection (LOD) of 0.285 nM. Besides, the designed aptasensor was successfully used to recognize Pb with excellent selectivity, reproducibility and stability in tap water and tea, providing a potential platform for Pb detection in actual samples.
ISSN:1873-4324