聚集诱导发光核酸适配体技术快速检测WSSV

Rapid detection of white spot syndrome virus using aggregation-induced emission aptamer technology

  • 摘要:
    目的 为实现对虾白斑综合征病毒 (WSSV) 现场快速筛查与早期诊断,本研究基于聚集诱导发光 (AIE) 原理,将WSSV核酸适配体与AIE分子四苯乙烯四羧酸钠 (TPE-(COOH)4Na) 结合,构建了一种用于特异性检测WSSV的荧光生物传感器。
    方法 通过反应体系优化、取样组织比选、特异性及灵敏度测定等系统性实验,验证了该传感器在临床检测中的可行性。
    结果 最佳反应体系为适配体浓度1 μmol/L,适配体与TPE-(COOH)4Na摩尔比为1∶120。在此条件下,以患病对虾肌肉组织为检测样本时,背景荧光信号显著低于内脏组织,表明肌肉组织为本方法的最佳取材部位。特异性实验结果表明,该传感器对WSSV呈现显著的荧光增强信号 (7 715 au.),荧光强度约为阴性对照组的2倍;而对虾血细胞虹彩病毒 (SHIV)、对虾传染性皮下及造血组织坏死病毒 (IHHNV) 及虾肝肠包虫 (EHP) 等常见虾类病原体仅引起微弱的背景荧光 (低于2 500 au.)。灵敏度实验表明,该传感器在检测患病对虾肌肉组织匀浆液时,其最低可检测到826 拷贝/μL的WSSV病毒。临床样本验证中,以24尾对虾样本为检测对象,本方法荧光强度检测结果与国标PCR法符合率达100%;365 nm紫外光下目视判读出现2例假阳性,提示该方法在弱阳性边界样本中存在一定局限性。
    结论 本研究成功建立了一种特异性强、灵敏度高的WSSV荧光适配体传感器。其核心优势在于无需核酸提取,操作简便,检测全程可在20 min内完成。该策略创新性地将AIE效应适配体传感技术应用于虾类病原体检测,为WSSV现场快速筛查与早期诊断提供了高性能新方法,同时为其他水产病原体的快速荧光传感检测提供了技术参考。

     

    Abstract: Aggregation-induced emission (AIE) is a photophysical phenomenon that contrasts with aggregation-induced quenching. To date, a substantial number of AIE-based chemosensors have been reported for the detection of biological targets, metals, and small organic compounds. Aptamers, emerging molecules comprising peptide and nucleic acid types, are widely used in sensor development and various biomedical applications. This study utilizes the Aggregation-Induced Emission (AIE) principle to combine a nucleic acid aptamer targeting white spot syndrome virus (WSSV) with the AIE molecule sodium tetraphenylethylene tetracarboxylate (TPE-(COOH)4Na), thereby constructing a fluorescent biosensor for the specific detection of WSSV. Through systematic experiments including reaction system optimization, tissue sample ratio selection, and specificity and sensitivity determination, the feasibility of this sensor for clinical detection was validated. The optimal reaction system consists of an aptamer concentration of 1 μmol/L and a molar ratio of aptamer to TPE-(COOH)4Na of 1:120. Under these conditions, when using diseased shrimp muscle tissue as the detection sample, the background fluorescence signal was significantly lower than that of visceral tissue, indicating muscle tissue as the optimal sampling site for this method. Specificity experiments demonstrated that the sensor exhibited a significant fluorescence enhancement signal (7 715 au.) for WSSV, with fluorescence intensity approximately double that of the negative control group. In contrast, common shrimp pathogens such as shrimp hemocyte iridovirus (SHIV), infectious hypodermal and hematopoietic necrosis virus (IHHNV), and epizootic hepatopancreatic cysticercosis (EHP) induced only weak background fluorescence (below 2 500 au). Sensitivity testing demonstrated that the sensor could detect as few as 826 copies/μL of WSSV viral particles in homogenized muscle tissue from infected shrimp. In clinical sample validation using 24 shrimp specimens, the fluorescence intensity results from this method showed 100% concordance with the national standard PCR method. However, visual interpretation under 365 nm UV light yielded 2 false positives, indicating limitations in weakly positive borderline samples. This study successfully established a highly specific and sensitive WSSV fluorescent aptamer sensor. Its core advantages include eliminating nucleic acid extraction, simplifying operation, and completing the entire detection process within 20 min. This strategy marks the first application of AIE-effect aptamer sensing technology for detecting shrimp pathogens, providing a high-performance new method for rapid field screening and early diagnosis of WSSV. It also offers a technical reference for rapid fluorescent sensing detection of other aquatic pathogens.

     

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