Shell-engineered chiroplasmonic assemblies of nanoparticles for zeptomolar DNA detection.

来自 Semantic Scholar

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150

作者：

Y Zhao，L Xu，W Ma，L Wang，H Kuang，C Xu，NA Kotov

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摘要：

DNA-bridged pairs of seemingly spherical metallic nanoparticles (NPs) have chiral geometry due to the nonideal oblong shape of the particles and scissor-like conformation. Here we demonstrate that deposition of gold and silver shells around the NP heterodimers enables spectral modulation of their chiroplasmonic bands in 400-600 nm region and results in significantly enhanced optical activity with g-factors reaching 1.21 × 10(-2). The multimetal heterodimers optimized for coupling with the spin angular momentum of incident enable polymerase chain reaction ()-based DNA detection at the zeptomolar level. This significant improvement in the sensitivity of detection is attributed to improvement of base pairing in the presence of NPs, low background for chiroplasmonic detection protocol, and enhancement of -plasmon coupling for light with helicity matching that of the twisted geometry of the heterodimers.

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关键词：

Nanoparticle assemblies chiroplasmonic properties core-shell deposition amplification biosensing

DOI：

10.1021/nl501166m

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年份：

2014