Construction And Application Of The Electroluminescent Biogenic Amines Sensors Based On Nanoclusters

Electrogenerated chemilumines-cence（ECL）,as a new type of electrochemical technology,is widely used in biological detection.It has plenty of characteristics,such as high sensitivity,wide linear range,low-cost,good controllability,simple sample pretreatment,fast detection and so on.Currently,different quantum dots（QDs）are used as emitters in ECL,and these QDs are limited in application of bioassay due to the inherent toxicity of heavy metals such as Cd²⁺and Pb²⁺in their structures.Moreover,many traditional organic luminescent agents are expensive and highly toxic.Thus,in order to reduce environmental pollution and economic loss,it is extremely necessary to develop a new low-toxic or non-toxic ECL"green"nanoluminescent species.While noble metal nanoclusters（Noble metal clusters,MNCs;size less than 2 nm）have attracted much attention in fluorescent biomarkers,chemical sensing and biosensor detection and practical applications due to their unique conductivity and excellent biocompatibility.Especially gold nanoclusters（Au NCs）and silver nanoclusters（Ag NCs）with special physical（optical,electronic）and chemical properties are used as electrochemiluminescent tags for chemical teleportation and image generation.Overall,the research and application of electrochemical sensors based on precious metal nanomaterials have great research value and application prospects.Because the gold nanoclusters protected by biomolecules have better biocompatibility,a new solid-state ECL bioamine sensor based on gold-silver bimetallic nanoclusters（Au-Ag BNCs）was developed in this paper.This study mainly includes the following:1.By studying the ECL of Au-Ag BNCs in K₂S₂O₈ system and the inhibition of its ECL by spermine,a simple ECL strategy based on Au-Ag BNCs for detecting SPM was designed.We used glutathione as a template to synthesize gold-silver bimetallic nanoclusters with high water solubility and red fluorescence for the first time.We found that it can produce strong cathodic electrochemiluminescence in K₂S₂O₈ system,and biopolyamine-spermine can inhibit Au-Ag BNCs ECL at the cathode.Based on this phenomenon,a simple Au-Ag BNCs liquid-phase ECL biorecognition system was constructed.This ECL system only needs to be performed in a homogeneous solution.Consequently,quantitative analysis of SPM can be achieved by this simple strategy without electrode modification.The detection concentration of SPM has a good linear relationship in the range of 1×10^-5-1×10^-3 M,and its limit of detection is 1.95×10^-6M.And the method has good stability,operability and practicability,showing a wide range of practical applications.2.Using Au-Ag BNCs liquid-phase ECL biorecognition system,a solid-state ECL sensor based on Au-Ag BNCs was developed to detect SPM.First,we modified the GCE electrode by self-assembly,and a new solid-state ECL bioamine sensor based on Au-Ag BNCs was designed by incorporating Au-Ag BNCs in a three-dimensional conductive hydrogel（PANI-ATMP）.Importantly,the results found that when the solid-state sensor uses Au-Ag BNCs as an emitter,it can generate a strong anode electrochemical luminescence signal in the TEA system,and SPM can significantly enhance the ECL signal strength of the anode.Therefore,we successfully constructed an SPM solid-state ECL sensor based on Au-Ag BNCs with a linear range of1×10^-12-1×10^-5 M and a minimum detection limit of 1.10×10^-13 M（S/N=3）.Research shows that the ECL sensor has a wide linear range and a low SPM detection limit,and has good stability and reproducibility.Therefore,bio-amine ECL sensors based on Au-Ag BNCs have great potential in biological applications.This research helps to provide new strategies for the development and application of various biosensors in the fields of biochemistry and nanoanalysis.