Label-free fluorescence DNA walker for protein analysis based on terminal protection and dual enzyme assisted cleavage induced G-quadruplex/berberine conformation.
Analyst
; 145(1): 46-51, 2019 Dec 16.
Article
in En
| MEDLINE
| ID: mdl-31755892
ABSTRACT
Development of a simple, fast, cost-efficient and sensitive approach for accurate protein analysis is of high significance due to its potential application in disease diagnosis and biomedicine research. Thus, we established a label-free fluorescence DNA walker for streptavidin detection based on terminal protection and dual enzyme assisted cleavage induced G-quadruplex/berberine conformation. In this paper, the swing arm probe and report probe were pre-assembled on gold nanoparticles. With the addition of a target, through the high-efficiency affinity between streptavidin and biotin in order to prevent the hydrolysis of exonuclease I, the swing arm probe which contains 8-17 DNAzyme cannot be destroyed and plays a role in the catalytic cleavage of the report probe, and the liberating fragment of the report probe which contains a specific sequence (5'-(TTAGGG)4) of G-quadruplex units can combine with berberine and shows an evident fluorescence signal enhancement. Our method, a sensitive and selective method of protein detection, achieves a 20 pM detection limit toward streptavidin. This developed DNA walker, which combines terminal protection and a dual enzyme assisted strategy, provides a prospective channel for streptavidin detection and should also be used for the design of biosensors in bio-detection and disease diagnosis.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Berberine
/
DNA Probes
/
Streptavidin
/
DNA, Catalytic
/
G-Quadruplexes
Language:
En
Journal:
Analyst
Year:
2019
Document type:
Article
Affiliation country:
China