Colloidal Au-enhanced surface plasmon resonance for ultrasensitive detection of DNA hybridization
Colloidal Au-enhanced surface plasmon resonance for ultrasensitive detection of DNA hybridization
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DOI：
10.1021/ja001215b
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发表时间：
2000-09-27
影响因子：
15
通讯作者：
Keating, CD
中科院分区：
文献类型：
--
作者：
He, L;Musick, MD;Keating, CD
描述了一种基于纳米颗粒放大表面等离子体共振（SPR）的超灵敏检测DNA杂交的新方法。与未扩增的结合事件相比，使用Au纳米颗粒标签导致角位移增加超过10倍，对应于靶寡核苷酸的灵敏度提高超过1000倍。SPR反射率的这种增强的偏移是大大增加的表面质量、Au颗粒的高介电常数以及An纳米颗粒与Au膜之间的电磁耦合的组合结果。DNA解链和消化实验进一步支持了这种方法在DNA杂交研究中的可行性;在粒子扩增SPR中观察到的极大的角位移使得在DNA阵列上进行SPR成像实验成为可能。在本工作中，采用宏观4 × 4阵列，并且类似于10 pM的定量限。对于24-mer寡核苷酸（表面密度小于或等于8 × 10（8）个分子/cm（2）），实现了最大化。即使没有进一步优化，该技术的灵敏度也开始接近传统的基于荧光的DNA杂交方法。这些结果说明了潜在的颗粒扩增SPR阵列为基础的DNA分析和超灵敏检测的寡核苷酸。
A new approach to ultrasensitive detection of DNA hybridization based on nanoparticle-amplified surface plasmon resonance (SPR) is described. Use of the Au nanoparticle tags leads to a greater than 10-fold increase in angle shift, corresponding to a more than 1000-fold improvement in sensitivity for the target oligonucleotide as compared to the unamplified binding event. This enhanced shift in SPR reflectivity is a combined result of greatly increased surface mass, high dielectric constant of Au particles, and electromagnetic coupling between An nanoparticles and the Au film. DNA melting and digestion experiments further supported the feasibility of this approach in DNA hybridization studies; The extremely large angle shifts observed in particle-amplified SPR make it possible to conduct SPR imaging experiments on DNA arrays.:ln the present work, macroscopic 4 x 4 arrays; were employed, and a similar to 10 pM limit of quantitation. was achieved for 24-mer oligonucleotides (surface density less than or equal to 8 x 10(8) molecules/cm(2)). Even without further optimization, the sensitivity of this technique begins to approach that of traditional fluorescence-based methods for DNA hybridization. These results illustrate the potential of particle-amplified SPR for array-based DNA analysis and ultrasensitive detection of oligonucleotides.