Synthesis Of Novel Chemiluminescence And Electrochemiluminescence Materials And The Design And Application Of Biosensors

This paper summarized the basic concepts,principles,common systems of chemiluminescence(CL)and electrochemiluminescence(ECL),and introduced the synthesis methods of CL luminescent materials,common ECL enhancement methods,the classification of ECL biosensors,the current status of acute myocardial infarction and its biomarkers etc.Because CL and ECL technologies do not have background interference caused by light scattering or autofluorescence,and have the advantages of simple device structure,high sensitivity,wide linear range and strong versatility,they have always been the research hotspot in the field of analytical chemistry.At present,many luminescent materials have been synthesized and a series of excellent biosensors based on CL and ECL have been developed,but the development of CL and ECL still faced some problems.For example,most CL materials exhibited weak and flash-type emission,which often leaded to poor analysis accuracy;the reproducibility of the ECL analysis method was not good enough,which would affect the accuracy of the analysis results;most of the coreagents needed in the traditional ECL analysis were not stable enough and non-environmentally friendly.How to further optimize the synthesis of luminescent reagents,improve the design schemes of biosensors,and obtain a more sensitive and accurate sensing platform still confront an enormous challenge.The article aimed to synthetize luminescent materials with superior performance to achieve more accurate analysis and detection,to develop more accurate and sensitive CL and ECL sensors for biomarkers(such as small molecules,proteins,and nucleic acids)and the physical and chemical properties of the internal environment(such as pH),and to provide new ideas for solving problems in practical applications.The details are as follows:1.By simultaneous incorporation of CL(luminol)and catalytic cofactor(hemin)into the scaffold of guanosine-derived hydrogel,we proposed an intensive and glow-type chemiluminescence(CL)hydrogel and carried out the preliminary detection of hydrogen peroxide(H2O2).The self-assembled hydrogel consisted of hemin/G4 structures,showing significant enzyme-like activity to the CL emission of luminol/H2O2.Due to a mechanism of slow-diffusion-controlled heterogeneous catalysis,blue light visible to naked eyes would come into being and last for over 8 hours after adding H2O2 into the hydrogel.And the CL emission images could be recorded by smartphone.The enhanced and glow-type CL emission could improve the reliability and precision of CL detection,which would have a promising application in cold light source and H2O2 detection of real biological samples.2.Based the encapsulation effect of surfactant CTAB during the formation of micelles,we synthesized an CL micelle which could tightly combine energy donor Bis(2-carbopentyloxy-3,5,6-trichlorophenyl)oxalate(CPPO)and energy receptor coumarin-545T(C-545T).Due to the sensitization of the micelle,CCC micelle exhibited high CL energy transfer energy efficiency and produced strong CL intensity.And we used CCC micelle to design a simple H2O2 sensing platform,which would have a promising application prospect in real serum samples.3.Based on the advantages of ratiometric ECL method to overcome environmental interference and eliminate false positive results,a dual-wavelength ratiometric ECL biosensor was designed for the detection of cardiac troponin I(cTnI),where Au nanoparticle modified graphitic phase carbon nitride nanosheet composite(Au-CNN)acts as an energy donor,(4,4'-dicarboxylic acid-2,2'-bipyridyl)ruthenium(?)(Ru(dcbpy)32+)and Au nanoparticle-loaded graphene oxide/polyethylenimine(GPRu-Au)nanomaterial acted as an energy acceptor.Au-CNN showed a high and steady ECL signal centered at 455 nm,which was well-matched with the adsorption of GPRu-Au.Thereby,we build a dual-wavelength ratiometric ECL biosensor via the highly efficient ECL resonance energy transfer(ECL-RET).This sensing platform exhibited outstanding analytical performance toward cTnI.The high reliability,selectivity,and sensitivity of this ratiometric ECL biosensor provided a versatile sensing platform for the bioanalysis.4.Combining the advantages of self-enhanced ECL that did not require additional coreactants and the simple modification of label-free sensing,we developed an ECL biosensor to detect miRNA-133a.We synthesized a highly luminescent and self-enhanced ECL nanohybrid(Ru-BCDs),which possessed the dual coreactive property as well as the intramolecular electron transfer process,which could minimize energy loss.The self-enhanced ECL nanohybrid was modified onto the electrode surface as ECL emitter.A carbon nitride nanosheet(CNN)was utilized to improve the stability of solid-state ECL.By utilizing the affinity discrepancy of the CNN to single-and double-stranded nucleic acids,a label-free and signal-on ECL biosensor was constructed for the determination of miRNA-133a.The designed biosensor exhibited good performance of miR-133a detection with a linear detection range of 500 fM-1 nM and a detection limit of 60 fM.The biosensor could realize simple and fast detection for targets,showed good stability and selectivity and could be used for the detection of real human serum with satisfactory results.5.Based on pH-dependent i-motif forming sequence and rolling circle amplification(RCA)strategy,a novel ECL pH sensor was proposed herein.Briefly,the pH sensor consisted of elaborately designed DNA:capture,primer and padlock.Among them,capture could be immobilized on the electrode surface via Au-S bond;the i-motif forming sequence of primer could hybridized with capture to form double strands;padlock was designed to partially complement with primer at both ends,and then circularized by ligase and acted as a template for RCA reaction.The RCA product can fold with hemin to form hemin/G-quadruplex DNAzymes(hemin/G4),thus greatly enhancing the ECL emission of luminol/H2O2.In alkaline solution,the single-stranded primer would not affect the hybridization and RCA reaction;instead,in acidic solution,primer would fold into i-motif structure,prevent hybridization and RCA reaction,andthus influence the formation of hemin/G4.The numbers of hemin/G4 showed positive relationship with the ECL intensity,therefore we build an ECL-pH sensor.The proposed sensor showed a good linear response range in physical pH range(pH 6-7.4)and could be employed for glucose detection in human serum sample.