Novel Electrochemiluminescence System Of Perylene And Its Derivatives For The Construction Of Signal Amplification Strategy In Biological Analysis

Electrochemiluminescence?ECL?analysis technology has become one of the research hotspots in bioanalysis due to its advantages of high sensitivity,good selectivity,fast response,easy operation and low cost.Increasing the sensitivity of analytical sensor and finding new ECL materials are still the research direction in ECL field.At present,the signal amplification strategies to improve the sensor sensitivity mainly include the nucleic acid amplification strategy,nanomaterials signal amplification strategy,co-reaction reagents signal amplification strategy and the novel co-reaction accelerators signal amplification strategy.The common ECL reagents,such as Ru complex,luminol,quantum dots and metal complexes,have disadvantages of high cost,complicated preparation and poor film-formation.Therefore,exploring simple,efficient,and sensitive new ECL system is particularly important for the development of ECL.Perylene and its derivatives,have large conjugated systems with excellent photoelectric properties,stability and high fluorescence quantum yield,are a kind of the new ECL materials with great development potential.This article mainly based on the new ECL performance of perylene and its derivatives,using different signal amplification strategies,for different biological analysis.The main research work of this paper is as follows:Part 1 Based on novel electrochemiluminescence of perylene derivative and dual signal amplification strategy for sensor constructionA novel perylene derivative?PTC-PEI?was first synthesized by covalent cross-linking between polyethylenimine?PEI?and pyrenetetracarboxylic acid?PTCA?,and the cathode ECL performance of PTC-PEI in aqueous solution was studied.And then,a sensitive ECL sensor with dissolved oxygen as an endogenous co-reaction reagent was established for the detection of Hg²⁺.The obtained PTC-PEI as a new type of ECL luminophor exhibited good stability and strong ECL response,providing a good foundation for the construction of the sensor.In order to further increase the sensitivity of the sensor,we used the dual signal amplification strategy combining the enzyme-assisted target cycle amplification with rolling circle amplification?RCA?strategy to enhance the ECL response.In RCA process,a long DNA sequence with G-rich bases was obtained by RCA to capture the hemin forming the hemin/G-quadruplex structure.It is worth pointing out that the hemin/G-quadruplex structure could effectively enhance the ECL intensity of PTC-PEI.Significantly,the structure,physicochemical properties and possible reaction mechanism of PTC-PEI were also studied in this work.In general,the target Hg²⁺sensor detection range is 0.1pmol/L-0.1?mol/L,and the detection limit is as low as 33 fmol/L?S/N=3?.Part 2 Based on dual co-reaction accelerator signal amplification strategy for electrochemiluminescence biosensor constructionIn this work,we used an anode electrochemiluminescence?ECL?phenomenon of perylene derivatives using H₂O₂ as a co-reaction reagent,and constructed ECL biosensor for sensitive laminin?LN,chronic liver disease biomarker?detection.At the same time,the possible ECL mechanism of this perylene derivative was explored.In the process of sensor construction,Ag and Fe-Fe₂O₃ nanoparticles were used as dual co-reaction accelerators to increase the ECL response of the perylene system,which could react with H₂O₂ at the anode to increase the formation of excited states of luminophor and further enhance the ECL response.Overall,based on this dual co-reaction accelerator signal amplification strategy,this sensor exhibited good sensitivity and selectivity with a detection limit as low as 0.03 pg/mL.At the same time,this immunosensor has been successfully used for the detection of patient serum samples,which exhibited an alternative pathways for the detection of other target?such as proteins,nucleic acid sequences,microRNAs,and cells?.Part 3 Based on perylene nanosheets and multiple target amplification signal amplification strategy constructing electrochemiluminescence biosensor.Lately,as a new type of electrochemiluminescence?ECL?material,perylene?Pe?and its derivatives have gained the attention of researchers because of their good photoelectric activity and controllability.However,the ECL of Pe all depended on organic solvents because of its strong large planar?-systems,which impeded its application in ECL biological analysis.In this work,we describe the ECL response from Pe nanosheet?PeNSs?in aqueous solutions prepared by a simple reprecipitation method.Herein,the Pe NSs were bound to GO-Au nanoparticles composites?GO-Au?via?-?stacking for preparing GO-Au-PeNSs.The GO-Au-Pe NSs were employed as ECL emitters using H₂O₂ as co-reactant and hemin/G-quadruplex as signal enhanced probe to establish a sensitive bio-sensor for miRNA detection.More importantly,this method enlarged the application of Pe and the dual signal amplification of miRNA-catalyzed hairpin assembly induced SDA process achieved a promising potential in disease rapid diagnosis.