Abstract

Nucleic acids in body fluids, such as circulating cell-free nucleic acids, viral DNA, and RNA have received much attention for their great potential as biomarkers in liquid biopsies of serious diseases. Although quantitative polymerase chain reaction (qPCR) has been traditionally used as a laboratory-based assay for measuring nucleic acids, there is a strong demand for techniques to qualitatively, rapidly, and simply measure the extremely low-abundance nucleic acids in order to realize the nucleic acid-based liquid biopsies. With this aim in mind, we developed a simple and highly sensitive sandwich-type assay for nucleic acids using a combination of surface-enhanced Raman scattering (SERS), which enhances Raman scattering by 10⁸– to 10¹⁰–fold, and bioorthogonal Raman tags, which generate signals in the biologically silent region (1800–2800 cm⁻¹). Using gold nanorods having approximately 240 strands of oligonucleotides and 4-cyano-N-(2-mercaptoethyl)benzamide (4CMB) as the bioorthogonal Raman tag, we successfully detected target nucleic acids in a sequence-selective manner.

摘要

体液中的核酸，例如循环中的无细胞核酸，病毒DNA和RNA，作为其在严重疾病的液体活检中的生物标记物的巨大潜力，受到了广泛的关注。尽管传统上将定量聚合酶链反应（qPCR）用作基于实验室的测定核酸的方法，但强烈需要定性，快速和简单地测定极低丰度核酸的技术，以实现核酸的定量分析。基于核酸的液体活检。为此，我们结合表面增强拉曼散射（SERS）开发了一种简单且高度灵敏的夹心型核酸测定方法，可将拉曼散射提高10 ⁸ – 10 ¹⁰折叠和生物正交拉曼标签，它们在生物沉默区域（1800-2800 cm ^-1）内产生信号。我们使用具有约240条寡核苷酸链的金纳米棒和4- cyano - N-（2-巯基乙基）苯甲酰胺（4CMB）作为生物正交拉曼标签，我们以序列选择的方式成功检测了目标核酸。