The Application Of PAMAM Dendrimer-coated Nanoclusters In Electrochemiluminescence Sensors

Electrochemiluminescence?ECL?has the advantages of easy control,low background signal and higher sensitivity compared to chemiluminescence and fluorescence.Although ECL for semiconductor quantum dots?QDs?and other triple bipyridylium compounds and their use in analytical chemistry have been reported,they are limited in their development in ECL sensors due to their priceiness,low luminous efficiency,and toxicity.Therefore,it is urgent to explore new efficient and recyclable ECL systems.Metal nanoclusters composed of several to several hundred metal atoms have drawn worldwide attention due to their extraordinary physical and chemical properties.In recent years,people are devoted to exploring potential diagnostic and therapeutic applications of metal nanoclusters.Currently,metal nanoclusters are used in bioanalysis,bioimaging,therapeutic applications,DNA assembly and logic gate construction,enzyme-based catalysis and thermometers and pH meters.Dendrimer is a class of hyperbranched polymers whose chemical properties are related to the nature of the end groups and can be arbitrarily changed to achieve the desired properties.Over the past 30 years,a variety of dendrimer with different chemical characteristics have been synthesized.However,commercial applications of these materials have not yet been well explored.Therefore,this article focuses on the use of polyamide-amine?PAMAM?dendrimer-coated Pt,Au metal nanoparticles on the impact of ECL in the field of bio-immunoassay,the major contents are as follows:1.Enhanced electrochemiluminescence of CdTe/Tripropylamine by dendrimer encapsulated Pt nanoparticles and its sensitive detection of catecholThe Pt dendrimer-encapsulated nanoparticles?Pt DENs?were synthesized by using amine-terminated sixth-generation PAMAM dendrimers and subsequently immobilized the Pt DENs onto glassy carbon electrode?GCE?surface.The highly enhanced ECL of CdTe QDs was achieved in tripropylamine?TPrA?solution with Pt DENs,and the ECL onset potential was shifted 0.08 V.The reason may be that Pt DENs exhibit high catalytic electrochemical oxidation in the presence of TPrA and excellent conductive property.Finally,catechol could be sensitively detected based on quenching of anodic ECL.The proposed ECL sensor exhibited good stability and selectivity.2.Fabrication of sandwich immunosensor based on dendrimer-coated platinum nanoparticles enhanced quantum dot electrochemiluminescenceBased on the ability of Pt DENs to enhance the ECL of CdTe/TPrA systems,we immobilized Pt DENs onto Fe₃O₄@SiO₂ nanomaterials as nanocarriers to amplify ECL signals,which can also be used as an effective carrier for capture antibodies?Ab₁?.CdTe QDs capped with 3-mercaptopropionic acid?MPA?serve as signal labels for the detection antibodies?Ab₂?,thus enabling the detection of CEA antigens.With an external magnet,the product separation is easy and convenient after each step.The constructed sandwich-type immunosensor has good stability,selectivity and reproducibility for detecting CEA.The use of immunosensors in serum samples can provide valuable information for early clinical diagnosis.3.Electrochemiluminescent behavior of dendrimer-coated gold nanoclusters and detection of 6-mercaptopurineWe used amine-terminated sixth-generation PAMAM dendrimers as gold nanoclusters?Au NCs?protective agent.The synthesized Au NCs with blue fluorescence used an incubation method and have no reducing agents.Compared with Au NCs synthesized with other protective agents,Au NCs synthesized by this method have higher sensitivity and selectivity.Using these traits,we proposed an ECL sensor for 6-MP detection with a detection range of 1-120 nM and the detection limit of 1 nM?S/D=3?.4.Enhanced electrochemiluminescence of DBAE/O₂ system in ethanol solution and detection of pentachlorophenolThe ethanol was added in DBAE/O₂ system enhanced the ECL intensity about 3 fold because ethanol-generated alkoxide radicals promoted ¹O₂ to excited state?¹O₂?^2*and the solubility of DBAE in water was improved.Based on the effective inhibition of PCP on the ECL response of DBAE/O₂,a simple ECL sensor for the PCP detection was fabricated.The ECL sensor exhibits a wide linear,low detection limit and good selectivity,and has a great potential for the detection of PCP in future.