The increasing incidence of hepatitis C viral (HCV) infection worldwide is a major concern for causing liver cirrhosis and hepatocellular carcinoma, leading to increased morbidity and mortality. Currently, the prevalence of HCV infection is estimated to be in the range of ∼3%. According to the World Health Organization, antiviral drugs can cure more than 95% of the HCV infected cases, if timely diagnosis and treatment are provided. The gold standard RT-qPCR assay is expensive and requires a minimum turnaround time of 4 h. Hence, a rapid and cost-effective detection assay that can be used even in resource-limited settings would be highly beneficial for mass level screening. Herein, we present an Au NP based facile strategy for rapid, early-stage, and sensitive detection of HCV RNA in clinical samples which avoids thiol tagging to the antisense oligonucleotide and expensive infrastructure. This technique utilizes the hybridization of a short-chain antisense oligonucleotide from the 5′ untranslated region (UTR) of the viral genome with the isolated HCV RNA samples. Using a specific sequence universal to all HCV genotypes—obtained through the NCBI BLASTn tool—the HCV positive samples have stabilized the citrate capped Au NPs against salt-induced aggregation, retaining their red color. On the other hand, negative controls, including HBV and HIV positive samples, do not stabilize the Au NPs, which results in purple coloration. Besides, the assay is successfully tested with a RNase A enzyme-treated HCV positive sample, which does not stabilize the Au NPs, thus confirming the role of the viral HCV RNA in this strategy. This Au NP based assay takes about 30 min using the viral RNA isolate and has high specificity with a detection limit of 100 IU mL⁻¹, which is ∼10 fold lower than the state-of-the-art Au NP based strategy.

中文翻译：

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裸眼比色法检测5'UTR靶向反义寡核苷酸和等离激元金纳米粒子介导的HCV RNA

在世界范围内，丙型肝炎病毒（HCV）感染的发病率不断上升，是引起肝硬化和肝细胞癌，导致发病率和死亡率增加的一个主要问题。目前，HCV感染的患病率估计在3％左右。根据世界卫生组织的资料，如果提供及时的诊断和治疗，抗病毒药物可以治愈95％以上的HCV感染病例。黄金标准的RT-qPCR分析价格昂贵，并且至少需要4小时的周转时间。因此，即使在资源有限的环境中也可以使用的快速且具有成本效益的检测方法，对于质量水平筛选将是非常有益的。在此，我们提出了一种基于金纳米颗粒的简便策略，用于快速，早期，对临床样品中的HCV RNA进行灵敏检测，避免了巯基标记反义寡核苷酸和昂贵的基础设施。该技术利用了来自病毒基因组5'非翻译区（UTR）的短链反义寡核苷酸与分离的HCV RNA样品的杂交。通过使用通过NCBI BLASTn工具获得的所有HCV基因型通用的特定序列，HCV阳性样品已稳定了柠檬酸盐封端的Au NP，防止盐诱导的聚集，并保持红色。另一方面，阴性对照（包括HBV和HIV阳性样品）不能使Au NP稳定，从而导致紫色。此外，使用不稳定金纳米颗粒的RNase A酶处理的HCV阳性样品成功测试了该测定，因此证实了病毒HCV RNA在该策略中的作用。使用病毒RNA分离物进行的基于Au NP的测定大约需要30分钟，并且具有高特异性，检测限为100 IU mL^-1，比最新的基于Au NP的策略低约10倍。