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Indexed by:期刊论文

Date of Publication:2011-06-15

Journal:BIOSENSORS & BIOELECTRONICS

Included Journals:SCIE、EI、PubMed

Volume:26

Issue:10

Page Number:4111-4116

ISSN No.:0956-5663

Key Words:Biosensor; DNAzyme; DNA cleavage; Fluorescence; Graphene

Abstract:A novel and promising "turn-on" fluorescent Cu2+ biosensor is designed based on graphene-DNAzyme catalytic beacon. Due to the essential surface and quenching properties of two-dimensional graphene, it can function as both "scaffold" and "quencher" of the Cu2+-dependent DNAzyme, facilitating the formation of self-assembled graphene-quenched DNAzyme complex. However, Cu2+-induced catalytic reaction disturbs the graphene-DNAzyme conformation, which will produce internal DNA cleavage-dependent effect. In this case, the quenched fluorescence in graphene-DNAzyme is quickly recovered to a large extent in 15 min. Compared with common DNAzyme-based sensors, the presented graphene-based catalytic beacon greatly improves the signal-to-background ratio, hence increasing the sensitivity (LOD = 0.365 nM). Furthermore, the controllable DNA cleavage reaction provides an original and alternative internal method to regulate the interaction between graphene and DNA relative to the previous external sequence-specific hybridization-dependent regulation, which will open new opportunities for nucleic studies and sensing applications in the future. (C) 2011 Elsevier B.V. All rights reserved.