基于HCR放大的无标记型荧光传感器的构建及H5N1 DNA检测

对于高致病性H5N1禽流感病毒，构建检测该病毒的高灵敏生物传感器，并与智能包装相结合用于实时监测，这对禽流感的防控具有重要意义。基于杂交链式反应（HCR）信号放大策略，以AgNCs作为荧光信号基团，构建了一种无标记“turn on”型荧光生物传感器用于检测代表H5N1病毒的H5N1基因序列。该传感器以H5N1 DNA作为触发剂引发HCR过程，使AgNCs产生强的荧光信号变化。研究表明，当H5N1 DNA浓度在0.2~800.0 nmol/L内，该传感器具有良好的响应信号，且在0.2~200.0 nmol/L之间的荧光强度与H5N1 DNA浓度呈线性相关，线性方程为y=10.982C+567.435（R2=0.992 73），检测限为176 pmol/L。核酸传感体系具有通用性，通过简单调整目标序列，可实现对不同目标物的特异性灵敏检测。该研究有望为高灵敏分析禽流感病毒标志物的通用传感平台设计提供思路。

Construction of Label-Free Fluorescence Sensor Based on HCR Amplification for Detection of H5N1 DNA

For the highly pathogenic H5N1 avian influenza virus, the construction of highly sensitive biosensors to detect the virus, combined with intelligent packaging for real-time detection, is of great significance for the prevention and control of avian influenza. Based on HCR signal amplification strategy and using AgNCs as fluorescence signal group, a labeled “turn on” fluorescent biosensor was constructed to detect H5N1 gene sequence representing H5N1 virus. The sensor used H5N1 DNA as a trigger to trigger the HCR process, which caused AgNCs to produce strong fluorescence signal changes. The research has shown that the sensor had a good response signal when the H5N1 DNA concentration was within 0.2~800.0 nmol/L, and the fluorescence intensity was linearly correlated with the H5N1 DNA concentration between 0.2~200.0 nmol/L. The linear equation was y = 10.982C + 567.435 (R2 = 0.992 73), and the detection limit was 176 pmol/L. The nucleic acid sensing system is universal, and can realize specific sensitive detection of different targets by simply adjusting the target sequence. This research is expected to provide ideas for the design of a universal sensing platform for highly sensitive analysis of avian influenza virus markers.