Nanotechnology & Catalysis Research Centre (NANOCAT), Institute of Graduate Studies, University of Malaya, Kuala Lumpur 50603, Malaysia.
Nanotechnology & Catalysis Research Centre (NANOCAT), Institute of Graduate Studies, University of Malaya, Kuala Lumpur 50603, Malaysia.
Biosens Bioelectron. 2019 Apr 15;131:214-223. doi: 10.1016/j.bios.2019.02.028. Epub 2019 Feb 19.
Surface-enhanced Raman scattering (SERS) based DNA biosensors have considered as excellent, fast and ultrasensitive sensing technique which relies on the fingerprinting ability to produce molecule specific distinct spectra. Unlike conventional fluorescence based strategies SERS provides narrow spectral bandwidths, fluorescence quenching and multiplexing ability, and fitting attribute with short length probe DNA sequences. Herein, we report a novel and PCR free SERS based DNA detection strategy involving dual platforms and short DNA probes for the detection of endangered species, Malayan box turtle (MBT) (Cuora amboinensis). In this biosensing feature, the detection is based on the covalent linking of the two platforms involving graphene oxide-gold nanoparticles (GO-AuNPs) functionalized with capture probe 1 and gold nanoparticles (AuNPs) modified with capture probe 2 and Raman dye (Cy3) via hybridization with the corresponding target sequences. Coupling of the two platforms generates locally enhanced electromagnetic field 'hot spot', formed at the junctions and interstitial crevices of the nanostructures and consequently provide significant amplification of the SERS signal. Therefore, employing the two SERS active substrates and short-length probe DNA sequences, we have managed to improve the sensitivity of the biosensors to achieve a lowest limit of detection (LOD) as low as 10 fM. Furthermore, the fabricated biosensor exhibited sensitivity even for single nucleotide base-mismatch in the target DNA as well as showed excellent performance to discriminate closely related six non-target DNA sequences. Although the developed SERS biosensor would be an attractive platform for the authentication of MBT from diverse samples including forensic and/or archaeological specimens, it could have universal application for detecting gene specific biomarkers for many diseases including cancer.
基于表面增强拉曼散射（SERS）的 DNA 生物传感器被认为是一种出色、快速和超灵敏的传感技术，它依赖于指纹识别能力来产生具有分子特异性的独特光谱。与传统的荧光基策略不同，SERS 提供了窄的光谱带宽、荧光猝灭和多路复用能力，以及与短长度探针 DNA 序列相匹配的拟合属性。在此，我们报告了一种新颖的、无 PCR 的基于 SERS 的 DNA 检测策略，该策略涉及两个平台和短 DNA 探针，用于检测濒危物种马来亚箱龟（MBT）（Cuora amboinensis）。在这种生物传感特征中，检测基于两个平台的共价连接，涉及氧化石墨烯-金纳米粒子（GO-AuNPs），其功能化有捕获探针 1 和金纳米粒子（AuNPs），修饰有捕获探针 2 和拉曼染料（Cy3），通过与相应的目标序列杂交。两个平台的耦合产生局部增强的电磁场“热点”，形成在纳米结构的连接处和间隙裂缝中，从而提供显著增强的 SERS 信号。因此，采用两个 SERS 活性基底和短长度探针 DNA 序列，我们设法提高了生物传感器的灵敏度，实现了低至 10 fM 的最低检测限（LOD）。此外，所制备的生物传感器甚至对目标 DNA 中的单个核苷酸碱基错配表现出灵敏度，并且显示出出色的性能来区分六个密切相关的非目标 DNA 序列。尽管开发的 SERS 生物传感器将成为从包括法医和/或考古样本在内的各种样本中鉴定 MBT 的有吸引力的平台，但它也可以用于检测许多疾病（包括癌症）的基因特异性生物标志物。
