Premium
A label‐free DNAzyme‐cleaving fluorescence method for the determination of trace Pb 2+ based on catalysis of AuPd nanoalloy on the reduction of rhodamine 6G
Author(s) -
Tang Meiling,
Wen Guiqing,
Luo Yanghe,
Kang Caiyan,
Liang Aihui,
Jiang Zhiliang
Publication year - 2015
Publication title -
luminescence
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.428
H-Index - 45
eISSN - 1522-7243
pISSN - 1522-7235
DOI - 10.1002/bio.2728
Subject(s) - rhodamine 6g , chemistry , fluorescence , deoxyribozyme , detection limit , quenching (fluorescence) , centrifugation , catalysis , rhodamine b , substrate (aquarium) , dna , analytical chemistry (journal) , photochemistry , nuclear chemistry , chromatography , organic chemistry , molecule , photocatalysis , biochemistry , physics , oceanography , quantum mechanics , geology
The substrate chain of double‐stranded DNA (dsDNA) could be specifically cleaved by Pb 2+ to release single‐stranded DNA (ssDNA) that adsorbs onto the AuPd nanoalloy (AuPdNP) to form a stable AuPdNP–ssDNA complex, but the dsDNA can not protect AuPdNPs in large AuPdNP aggregates (AuPdNPA) under the action of NaCl. AuPdNP–ssDNA and large AuPdNPA could be separated by centrifugation. On increasing the concentration of Pb 2+ , the amount of released ssDNA increased; AuPdNP–ssDNA increased in the centrifugation solution exhibiting a catalytic effect on the slow reaction of rhodamine 6G (Rh6G) and NaH 2 PO 2 , which led to fluorescence quenching at 552 nm. The decrease in fluorescence intensity (Δ F ) was linear to the concentration of Pb 2+ within the range 0.33–8.00 nmol/L, with a detection limit of 0.21 nmol/L. The proposed method was applied to detect Pb 2+ in water samples, with satisfactory results. Copyright © 2014 John Wiley & Sons, Ltd.