Zhou Qingzhen, Yan Hongxia, Ran Fengying, Cao Jianjun, Chen Long, Shang Bing, Chen Hao, Wei Jian, Chen Qinhua
Affiliated Dongfeng Hospital, Hubei University of Medicine Hubei Shiyan 442008 China
Department of Radiotherapy, Hubei Cancer Hospital 116 South Zuodaoquan Road Wuhan 430074 China.
RSC Adv. 2018 Jul 19;8(46):25955-25960. doi: 10.1039/c8ra04721a.
Sensitive detection of vascular endothelial growth factor (VEGF) is important for early cancer disease diagnosis in the clinic. A sensitive fluorescent sensing platform for VEGF detection is developed in this work. It is based on a target-triggered hybridization chain reaction (HCR) and graphene oxide (GO) selective fluorescence quenching. In this assay, in the presence of the VEGF, the hairpin structure of Hp opens up and the initiation sequence will be exposed to Hp1 to open its hairpin structure. Then the opened Hp1 hybridizes with Hp2 to expose the complementary sequence of Hp1 which hybridizes with Hp1 again by HCR. Thus HCR would be initiated, generating super-long dsDNA. After the HCR, the double strands of the HCR product cannot be adsorbed on the GO surface. As a result, the HCR product gives a strong fluorescence signal which is dependent on the concentration of VEGF. By using VEGF as a model analyte, the assay provides a highly sensitive fluorescence detection method for VEGF with a detection limit down to 20 pg mL. The proposed aptasensing strategy based on target-triggered HCR amplification can thus be realized. It was successfully applied to the determination of VEGF in spiked human serum, urine and saliva. Therefore, it can easily have wide applications in the diagnosis of vital diseases.
血管内皮生长因子（VEGF）的灵敏检测对于临床癌症疾病的早期诊断至关重要。本研究开发了一种用于检测VEGF的灵敏荧光传感平台。它基于目标触发的杂交链式反应（HCR）和氧化石墨烯（GO）的选择性荧光猝灭。在该检测方法中，在VEGF存在的情况下，发夹结构的Hp打开，起始序列将暴露出来与Hp1结合，从而打开其发夹结构。然后打开的Hp1与Hp2杂交，暴露Hp1的互补序列，该序列通过HCR再次与Hp1杂交。这样就会引发HCR，产生超长双链DNA。HCR之后，HCR产物的双链不能吸附在GO表面。结果，HCR产物发出强烈的荧光信号，该信号取决于VEGF的浓度。以VEGF作为模型分析物，该检测方法为VEGF提供了一种高灵敏的荧光检测方法，检测限低至20 pg/mL。基于目标触发的HCR扩增的所提出的适体传感策略因此得以实现。它已成功应用于加标的人血清、尿液和唾液中VEGF的测定。因此，它能够轻松地在重大疾病诊断中得到广泛应用。
