Studies Of Lightweight Nanomaterial-based IL-17A Immunosensors

Psoriasis is a chronic inflammatory skin immune disease influenced by genes and external environment,with high incidence and easy recurrence.Studies have shown that interleukin 17A(IL-17A)plays a dominant role in the pathogenesis of psoriasis and can be used as a diagnostic marker for psoriasis.Accurate detection of IL-17 A content is of great significance for the prevention and treatment of psoriasis.Immunodetection methods based on antigen-antibody interaction have high selectivity and are widely used in the field of biological detection.Nanomaterials as carriers greatly improve the sensitivity of immunodetection methods.However,traditional nanomaterials have high density and complicated modification steps,which will generate large background signals and poor reproducibility.The main research purpose of this thesis is to develop an immunoassay method using lightweight functionalized nanomaterials as a carrier to achieve ultrasensitive quantitative detection of IL-17 A.The specific research contents are as follows:(1)Based on the traditional enzyme-linked immunosorbent assay(ELISA)detection method,light-weight polystyrene@polydopamine(PS@PDA)nanoparticles with core-shell structure were designed as carriers of enzymes and antibodies.The overall density of PS@PDA is small,which can greatly reduce the non-specific adsorption caused by natural sedimentation.The quinone groups on the surface of PS@PDA can undergo Michael addition reaction with antibodies and enzymes to form stable bioconjugates and maintain the biological activities of enzymes and proteins to a large extent.The data results show that the ELISA detection method based on PS@PDA nanoparticles has high stability and high signal-to-noise ratio.This method was used to detect IL-17 A with a dynamic range of 0.31 to 80 pg/m L and a detection limit of0.18 pg/m L.The recovery rate of healthy human serum samples was higher than 90%,indicating that PS@PDA-ELISA has good accuracy and precision.Therefore,the detection method has certain guiding significance for the clinical diagnosis of psoriasis.(2)An electrochemical immunosensor based on modified zeolite imidazolate framework-8(ZIF-8)was designed for the electrochemical immunodetection of IL-17 A.Hollow thin-layer ZIF-8 nanoparticles(e ZIF-8)were obtained by synthesizing small-sized ZIF-8 nanoparticles in aqueous solution,and using tannic acid to etch and modify ZIF-8.The electrochemical immunosensor using e ZIF-8 as a signal amplifying carrier has simple operation and strong specificity.The dynamic range for detecting IL-17 A is 0.5-30 pg/m L,and the detection limit reaches 0.4pg/m L.The recovery rate of healthy human serum samples was between94% and 105%,indicating that the sensor has high accuracy.The results of this immunosensor on IL-17 A in serum of patients with psoriasis were consistent with those reported in the literature.The sensor provides a new method for the detection of IL-17 A.