High-sensitive immunosensing of protein biomarker based on interfacial recognition-induced homogeneous exponential transcription

novel and versatile immunosensing strategy was developed for ultrasensitive and specific detection of.proteins by organically integrating interfacial specific target recognition and homogeneous transcription.amplification. In principle, classic antigen-antibody sandwich structure on the microplate could realize.the specific identification of target protein. Biotinylated DNA probe was subsequently introduced by.streptavidin-biotin system as a bridge linking interfacial and homogeneous reaction. The biotinylated.DNA initiated exponential transcription amplification in the solution, which converted per target.recognition event on the interface to numerous single-stranded RNA products in solution for highly.sensitive fluorescence immunosensing. The proposed immunoassay based on interfacial recognitioninduced.homogeneous exponential transcription (IR-HET) for vascular endothelial growth factor.(VEGF) detection showed a good linear range from 0.01 to 1000 pg/mL and the limit of detection as low.as 1 fg/mL, which was 3 orders lower than traditional ELISA method. The established strategy was also.successfully applied to directly detect VEGF from culture supernatants of tumor cells and clinical body.fluid samples, proving very high sensitivity, selectivity and low matrix effect. Therefore, IR-HET-based.immunosensing strategy might become a potential powerful tool be applied in ultrasensitive detection.of low abundance protein biomarker for clinical early diagnosis, treatment and prognosis

通过有机地整合界面特定的靶标识别和均匀转录，开发了新型和多功能的免疫传感策略，用于对蛋白质的超敏和特异性检测。原则上，微孔板上的经典抗原抗体夹层结构可以实现。靶蛋白的特定鉴定。随后，由链霉亲和素 - 生物素系统引入了生物素化的DNA探针，作为连接界面和均匀反应的桥梁。生物素化。DNA在溶液中启动了指数转录扩增，该溶液每个靶标转换。界面上的识别事件转换为溶液中许多单链RNA产物，以进行高度敏感的荧光免疫传感。基于界面识别诱导的拟议的免疫测定。均匀指数转录（IR-HET）用于血管内皮生长因子。（VEGF）检测表明，线性范围为0.01至1000 pg/ml的良好线性范围为1000 pg/ml，检测极限为低。既定的策略也得到了成功，可实现从肿瘤细胞和临床体的培养上清液中直接检测VEGF。流体样品证明了非常高灵敏度，选择性和低基质效应。因此，基于IR-HET的免疫传感策略可能会成为一种潜在的强大工具