Intensive And Long-lasting Chemiluminescence Functionalized Materials And Their Applictions

In this dissertation,the basic concepts of chemiluminescence?CL?,the state of the art in the development of chemiluminescence functionalized materials?CFMs?and their applications in chemiluminescence based bioassays were reviewed.CFMs possess excellent CL activity,biocompatibility,ease of self-assembly and good stability etc.,leading to their broad applications as analytical probes or interfaces in CL based bioassays.The overwhelming majority of known CFMs exhibit flash-type emission,which have been applied to detect all kinds of analytes with high sensitivity and wide dynamic range in the fields of clinical diagnostics,food safety,environmental monitoring etc.However,the flash CL reactions occur quickly,which often leads to large measuring error and limits their applications.Intensive and long-lasting CL emission has been pursued for many decades in CL field.In analytical chemistry,a constant CL emission within analytical time could improve analytical accuracy and reproducibility.In addition,the existing synthetic methods for CFMs are usually laborious and tedious,and suffer from the reagent leaking issue etc.How to further improve the synthetic protocol and optimize the combination of the CL reagents,catalysts and the nanomaterials so as to obtain CFMs with superior CL properties remains a great challenge.In this work,two kinds of highly intensive and long-lasting CFMs were synthesized,and their CL intensity and persistence were studied.The CL mechanism has been also proposed.On the other hand,a novel synthetic strategy for preparing CFMs without additional chelating agents as linkers for CL reagents or catalysts was proposed,and two kinds of CFMs were synthesized thereby.Their CL properties were investigated.A label-free CL immunosensor for rapid and sensitive detection of acute myocardial infarction?AMI?biomarker,copeptin,was developed.The main results are as follows:1.We report for the first time firefly-mimicking intensive and long-lasting CL hydrogels consisting of chitosan,CL reagent N-?4-aminobutyl?-N-ethylisoluminol?ABEI?and catalyst Co²⁺.The light emission was even visible to naked eyes and lasted for over 150 hours when the hydrogels was mixed with H₂O₂.The results demonstrated that 99.8%Co²⁺was immobilized at the skeleton of the CS hydrogels,and 89.5%ABEI existed in aqueous phase.The intensive and long-lasting CL emission was attributed to the synergistic effect of Co²⁺,ABEI and the porous network structure of the hydrogels through a slow-diffusion-controlled heterogeneous catalytic reaction.Co²⁺ located at the skeleton of the chitosan hydrogels as an active site catalyzed the decomposition of H₂O₂ that slowly diffused to the active site,followed by the reaction with ABEI to generate intensive and long-lasting CL.This mimics firefly bioluminescence system in terms of intensity,duration time and catalytic characteristic,representing a new concept in developing intensive and long-lasting CL materials for potential applications in cold light sources,bioassays,biosensors and biological imaging.2.CL reagent ABEI functionalized CaCO₃ microspheres with a dual-catalytic system consisting of Co²⁺ and horseradish peroxidase?HRP?(HRP/ABEI/Co²⁺-CaCO₃ MPs)were synthesized via a facile method for the first time.They exhibited highly intensive"glow-type"CL emission,which was visible by naked eyes in a dark room for 8 hours.The HRP/ABEI/Co²⁺-CaCO₃ with dual catalytic system produced more intensive"glow-type"CL emission in the first 3 hours as compared with ABEI/Co²⁺-CaCO₃ and HRP/ABEI/CaCO₃,both of which merely possessed a single catalyst in their systems.Moreover,the CL intensity of HRP/ABEI/Co²⁺-CaCO₃ MPs during the first hour outperforms all the previously reported long-lasting chemiluminescence functionalized micro/nanomaterials,such as the firefly-mimicking intensive and long-lasting ABEI/Co²⁺/chitosan hydrogels.The outstanding CL performance of HRP/ABEI/Co²⁺-CaCO₃ MPs is attributed to high loading of CL reagents and catalysts in CaCO₃ MPs and high catalytic efficiency and good stability of the dual catalytic system consisting of Co²⁺complex and HRP.The HRP/ABEI/Co²⁺-CaCO₃ MPs are neutral materials with highly intensive and persistent emission as well as good biocompatibility,rendering them excellent biomaterials for various bioassays.We envisage that this excellent material holds great promise in vast application fields,such as bioassays,bioimaging,environmental monitoring,and life science etc.3.ABEI and Co²⁺ bifunctionalized polydopamine(Co²⁺-ABEI-PDA)nanospheres were synthesized via a facile strategy for the first time by making full use of the abundant functional groups in polydopamine.Firstly,PDA nanospheres were formed by dopamine self-polymerization under alkaline conditions.Then,ABEI molecules were covalently linked to the benzene ring of PDA through Michael Addition Reaction,and Co²⁺ catalysts were further coordinated with the N atom in pyrrole and hydroxyl group of catechol in PDA,leading to simultaneous loading of abundant ABEI and Co²⁺ in PDA.Finally,Co²⁺-ABEI-PDA nanospheres were obtained.The Co²⁺-ABEI-PDA were mono-dispersed sphericity with the average diameter of 248±48 nm.The as-prepared Co²⁺-ABEI-PDA exhibited excellent CL properties.The CL intensity of Co²⁺-ABEI-PDA was nearly 4000 times higher than that of ABEI functionalized polydopamine?ABEI-PDA?nanospheres with no catalyst in the system.Besides,the CL intensity of Co²⁺-ABEI-PDA outperforms those of various metal ion-ABEI-PDA by using other metal ion,such as Cr³⁺,Pb²⁺,Fe²⁺,Fe³⁺,Cu²⁺,Cd²⁺,Mn²⁺,Hg²⁺,Ni²⁺,and Au³⁺,in the replacement of Co²⁺.The outstanding CL performance of Co²⁺-ABEI-PDA is attributed to the combination of the two following merits:the inhibition to the free radical scavenging ability of PDA by Co²⁺immobilized on PDA,and superior catalytic effect to ABEI-H₂O₂ system provided by Co²⁺ coordinated on PDA.By aptly selecting proper nanomaterials with abundant functional groups as carriers for CL reagents and catalysts,novel CFMs with superior CL performance were obtained.This finding offers a new guideline to design efficient CFMs with superior CL performance.4.Multi-functionalized polydopamine nanospheres Co²⁺-ABEI-AuNPs-PDA were synthesized via a similar strategy as the previous work by further taking advantage of the good reducibility and biocompatibility of polydopamine.The Co²⁺-ABEI-AuNPs-PDA were mono-dispersed sphericity with the average diameter of 266±59 nm.The as-prepared Co²⁺-ABEI-AuNPs-PDA exhibited excellent CL properties.On this basis,a label-free CL immunoassay for detecting copeptin was developed by conjugating copeptin antibody to Co²⁺-ABEI-AuNPs-PDA via AuNPs to form an immunoassay interface with excellent CL properties.The approach could determine copeptin in the range of 10^-12g/mL?10^-7 g/mL with a detection limit of 3.25×10^-13 g/mL.It also possessed good stability and reproducibility,and was capable of detecting copeptin in the serum samples of AMI patients.This excellent analytical strategy holds great promise in the rapid and sensitive diagnosis of AMI.