la8b01576_si_001.pdf (816.57 kB)
Lighting Up Fluorescent Silver Clusters via Target-Catalyzed Hairpin Assembly for Amplified Biosensing
journal contribution
posted on 2018-07-25, 00:00 authored by Min Pan, Meijuan Liang, Junlin Sun, Xiaoqing Liu, Fuan WangIsothermal
enzyme-free nucleic acid circuits have been developed
for carrying out diverse functions ranging from dictate biocomputing
to amplified biosensing. Catalytic hairpin assembly (CHA), the catalyzed
cross-opening of two hairpin substrates by an initiator, has attracted
increasing attention because of its facile design and high amplification
capacity. The complex labeling and frequent photobleaching of a conventional
fluorescent CHA biosensor still remains a challenge that needs to
be solved. Herein, we constructed a new label-free and enzyme-free
isothermal CHA lighting up AgNCs strategy for amplified nucleic acid
assay by integrating the interfacially and spatially sensitive feature
of DNA-templated fluorescent silver nanoclusters (DNA-AgNCs) and the
high signal amplification capability of the CHA circuit. In this strategy,
one polyguanine-grafted hairpin and the other AgNCs-capturing hairpin
were engineered as assembly constitutes, which were kinetically impeded
from cross-hybridizations without target. However, in the presence
of target, the CHA-catalyzed assembly of two functional hairpins was
successively progressed and concomitantly accompanied by an efficient
accommodation of AgNCs to the polyguanine-elongated dsDNA product,
leading to highly efficient AgNCs-lighting up and to the generation
of an amplified fluorescence signal. As a simple mix-and-detect strategy,
the isothermal enzyme-free CHA-mediated lighting up AgNCs (CHA-AgNCs)
system provided a facile visualization way for amplified detection
of DNA with a detection limit of 20 pM, which was comparable to or
even better than some enzyme-involved amplification methods. The homogeneous
CHA-AgNCs system can be used as a general sensing platform and be
easily adapted for analyzing other biologically important analytes,
for example, microRNA (miRNA), by introducing the sensing module consisting
of an auxiliary hairpin through an easy-to-integrate procedure. By
taking advantage of the signal amplification features of CHA and the
robust AgNCs-lighting up procedure, we anticipate that the CHA-lighting
up AgNCs system can provide an important tool for biomedicine and
bioimaging applications and thus should hold great promise in clinical
diagnoses and treatment fields.
History
Usage metrics
Keywords
detection limitAgNCs strategyAgNCs systemCHA-catalyzed assembly20 pMmix-and-detect strategysilver nanoclustersenzyme-free CHA-mediated lightingtreatment fieldshairpin substratesTarget-Catalyzed Hairpin Assemblypolyguanine-grafted hairpinsignal amplification capabilityAgNCs-capturing hairpinamplification capacityCHA-AgNCs systemfluorescence signalacid circuitsCatalytic hairpin assemblyacid assayAmplified Biosensing Isothermal enzyme-freeeasy-to-integrate procedureCHA lightingbioimaging applicationsenzyme-involved amplification methodssignal amplification featuresCHA circuitCHA biosensorFluorescent Silver Clusterspolyguanine-elongated dsDNA productvisualization way
Licence
Exports
RefWorks
BibTeX
Ref. manager
Endnote
DataCite
NLM
DC