Construction And Application Of Signal Enhanced Electrochemical Luminescent Immunosensor Based On Photonic Crystal

With the continuous increase of human activities,many emerging infectious diseases have appeared and broke out in the crowd,posing a serious threat to economic and social development as well as human life and health.Therefore,the development of economical and efficient immunological detection methods has become an important scientific issue in the field of disease detection.Electrochemiluminescence immunosensors have become an important means of disease detection due to their unique advantages.How to enhance the intensity of the electrochemiluminescence signal and improve the detection sensitivity of immunosensors has attracted wide attention from researchers.In this paper,based on the effect of photonic crystal to increase optical gain,combining photonic crystals with electrochemiluminescent immunosensors,two novel signal-enhanced electrochemiluminescent immunosensors was successfully constructed and applied to the efficient detection of Zika virus(ZIKV).The main research contents are as follows:1.Construction of an electrochemiluminescence immunosensor with enhanced silica photonic crystal signalIn this work,we deposited a silicon dioxide photonic crystal film on the surface of the ITO electrode by vertical deposition method,and modified ZIKV antibody as the capture probe on the surface,and ZIKV antibody labeled with ruthenium bipyridine was used as the signal probe to construct an electrochemiluminescence immunosensor with enhanced silica photonic crystal signal.The electrochemiluminescence method was used to detect ZIKV antigen under optimized experimental conditions.The linear range was 1 fg/m L-1 ng/m L,and the minimum detection limit was 0.3 fg/m L.The high sensitivity of this immunosensor is attributed to the good optical gain effect and biocompatibility of silica photonic crystals.In addition,the electrochemiluminescent immunosensor has the advantages of strong specificity,good stability,low cost and simple preparation,which shows that the electroluminescent immunosensor with enhanced silica photonic crystal signal has broad application prospects in antigen immunodetection.2.Construction of low potential electrochemiluminescence immunosensor based on photonic crystal signal enhancementAlthough ruthenium bipyridine has a high electrochemiluminescence efficiency,its high excitation potential can cause oxidative damage to biomolecules.In order to reduce the oxidative damage of biomolecules,in this study,a single layer of polystyrene photonic crystal film modified on ITO was used as a template to deposit a gold layer in the photonic crystal gap by electrochemical methods,And the photonic crystal template gold layer electrode that emits electrochemistry at low potential was prepared.The silica nanoparticles(Ru@SiO₂)doped with ruthenium bipyridine were modified with ZIKV antibody as a signal probe.The signal probe was assembled on the surface of the sensor by sandwich immune reaction,and the ZIKV antigen was quantitatively detected by electrochemiluminescence.The related research results show that the electrochemiluminescence immunosensor achieved the detection of ZIKV antigen at low potential(0.95 V),which was about 0.2 V lower than that of the conventional electrochemiluminescence potential of bipyridine ruthenium(1.15 V).This was due to that the presence of photonic crystals avoided the direct contact of Ru@SiO₂ particles with the electrode surface and inhibited the oxidation of bipyridine ruthenium on the electrode surface,which made the spatial separation of the initial electrochemical reaction and the chemiluminescent reaction.Finally,a low-potential electrochemiluminescence induced by tripropylamine oxidation was obtained.In addition,the detected electroluminescence signal and the logarithm of ZIKV antigen concentration showed a good linear relationship in the range of 0.1 fg/m L?1ng/m L.This result indicates that the detection sensitivity of the photonic crystal is enhanced to a certain extent due to the enhanced effect of electrochemiluminescence.At the same time,the immunosensor has good selectivity and reproducibility.This study provides a highly sensitive immunoassay platform with potential application prospects in the field of low-potential electrochemiluminescence immunoassays.In this paper,photonic crystals are introduced into immunosensors,two simple and efficient electrochemiluminescence immunosensor was prepared,which realizes the effective enhancement of the electrochemiluminescence signal and improves the sensitivity of immunodetection.This study provides a new research strategy for the enhancement of electrochemiluminescence signals,and provides a strong technical support for the rapid detection of antigens and antibodies.