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Ultrasensitive electrochemical biosensor for silver ion based on magnetic nanoparticles labeling with hybridization chain reaction amplification strategy
journal contribution
posted on 2017-10-01, 00:00 authored by Y Zhang, H Li, M Chen, X Fang, P Pang, H Wang, Z Wu, Wenrong YangWenrong YangSilver ion (Ag + ) is a highly toxic heavy metal ion to aquatic organisms and accumulates in the human body via the food chain. Therefore, fast and accurate detection of Ag + in water and food resources has become a critical issue within the scope of human health. Herein, we developed an ultrasensitive electrochemical biosensor for detection of Ag + based on magnetic Fe 3 O 4 @gold core-shell nanoparticles (Fe 3 O 4 @Au NPs) labeling with hybridization chain reaction (HCR) amplification strategy. In this sensing strategy, the magnetic Fe 3 O 4 @Au NPs were selected for labeling with HCR product and enrichment on the surface of magnetic gold electrode. Thiolated-oligonucleotide (S1) was firstly immobilized on the surface of Fe 3 O 4 @Au NPs through Au–S chemical bond. In the presence of Ag + , cytosine-rich DNA oligonucleotide S2 hybridized with S1 to form an intramolecular duplex, in which Ag + can selectively bind to cytosine–cytosine mismatches forming C–Ag + –C complex. The exposed stem of the C–Ag + –C complex opened two alternating ferrocene-labeled DNA hairpins (H 1 and H 2 ) in turn and triggered HCR to form a supersandwich DNA structure on the surface of Fe 3 O 4 @Au NPs. The HCR products modified Fe 3 O 4 @Au NPs were brought to the surface of magnetic gold electrode for direct electrochemical measurements. The proposed strategy led to a low detection limit of 0.5 fM and a wide dynamic range of 1 fM–100 pM for target Ag + . The developed biosensor was highly selective and its practical applicability in tap water and lake water samples was also investigated with a satisfactory result.
History
Journal
Sensors and actuators, b: chemicalVolume
249Pagination
431 - 438Publisher
ElsevierLocation
Amsterdam, The NetherlandsPublisher DOI
ISSN
0925-4005Language
engPublication classification
C Journal article; C1 Refereed article in a scholarly journalCopyright notice
2017 ElsevierUsage metrics
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No categories selectedKeywords
Silver ionMagnetic nanoparticlesCytosine–Ag+–cytosineHybridization chain reactionElectrochemical biosensorScience & TechnologyPhysical SciencesTechnologyChemistry, AnalyticalElectrochemistryInstruments & InstrumentationChemistryCytosine-Ag+-cytosineHEAVY-METAL IONSPLASMA-MASS SPECTROMETRYSENSITIVE DETECTIONFE3O4 NANOPARTICLESSELECTIVE DETECTIONGOLD NANOPARTICLESDOPED GRAPHENEDNA SENSORWATERAPTASENSOR
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