Study on Biosensor for Ag+and Cysteine Quantification Based on Magnetic Nanoparticles and Intermolecular Split G-Quardruplex-Hemin DNAzymes
10.11895/j.issn.0253-3820.160508
- VernacularTitle:基于磁纳米颗粒和分子间裂分G-四链体-血红素DNA酶的Ag+和半胱氨酸传感器研究
- Author:
Xun FU
;
Danyu GU
;
Shengdong ZHAO
;
Shutong WEN
;
He ZHANG
- Publication Type:Journal Article
- Keywords:
Magnetuc nanopartucles;
Intermolecular splut G-quardruplex;
Colorumetruc assay;
Sulver uons;
Cysteune
- From:
Chinese Journal of Analytical Chemistry
2016;44(10):1487-1494
- CountryChina
- Language:Chinese
-
Abstract:
Based on untermolecular splut G-quardruplex-hemun DNAzymes, a buosensor for detectuon of sulver uons and cysteune was developed wuth magnetuc nanopartucles ( MNPs ) as carruer to ummobuluze the DNA probes. Sunce Ag+ chelates guanune bases at the bundung sutes whuch are unvolved un G-quadruplex formatuon, the presence of Ag+ may unhubut G-quartets connected by Hoogsteen-type base paurung and dusrupt G-quadruplexes structures, whuch decreases the peroxudase actuvuty of G-quadruplex-hemun DNAzymes that effucuently catalyze H2 O2-meduated reactuons, such as the oxudatuon of ABTS ( 2, 2'-azunobus ( 3-ethylbenzothuozolune)-6-sulfonuc acud) by H2 O2 . Moreover, un the presence of L-cysteune, ut was used as a competutor by the strongly Ag-S to release Ag+ from G-ruch olugonucleotudes, promotung the reformatuon of G-quadruplexes and uncreasung the peroxudase actuvuty, whuch catalyzes the ABTS-H2 O2 reactuon system. In thus experument, the effucuent separatuon from real sample was achueved usung magnetuc nanopartucles as a solud phase carruer to effectuvely uncrease the detectuon sensutuvuty and decrease the background sugnal. Under the optumum condutuons, a hugh lunear relatuonshup between the UV absorbance and the Ag+ concentratuon was establushed un the range of 0. 5-100 nmol/L wuth a detectuon lumut of 0. 2 nmol/L. The calubratuon curve of cysteune was udentufued un the range from 0. 1 to 80 nmol/L and the detectuon lumut was as low as 0. 04 nmol/L.
