Research And Application Of Sulfur Andsulfide Nano Materials In Sensors

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.It is well-known that an efficient coreactant could greatly enhance the ECL siganl of the emitter.Therefore,in order to improve the sensitivity of biosensors,one of the most important ways is to develop an efficient ECL system.Nanomaterials with high surface area and excellent surface activity could effectively increase the reactivity of electrochemical interface for further increasing the ECL performance.Moreover,ECL nanomaterials?e.g.,quantum dots and metal nanoclusters?with excellent ECL properties have been extensively applied in ECL bioassay.Herein,nanomaterials were employed to enhance reacted efficiency of coreactants and develop low-cost,biocompatible and high-performance ECL emitters to construct the sensitive ECL biosensors for the detection of proteins and small biomolecules.At the same time,real-time and accurate pH monitoring is one of the core tasks in the fields of industrial production,biomedicine,and environmental protection.We have built ECL and FL pH sensors based on SQDs-MOFs compounds.The detail contents are divided into the following aspects:1.Based on the silver nanoparticles functionalized CoS nanoflowers as co-reaction acceleratores for electrochemiluminescence biosensor constructionMetal oxide semiconductor nanocrystals?NCs?have attracted particular research interests due to low cost and good biocompatibility.Herein,the bis-coreaction accelerator of silver nanoparticles functionalized CoS nanoflowers?Ag@CoS NFs?were first prepared by in situ generating silver nanoparticles on the surface of CoS NFs via silver mirror reaction.Due to the synergistic catalysis between CoS NFs and Ag NPs,the decomposition rate of the co-reaction reagent H₂O₂ was largely improved,generating more ROS for signal amplification.Using the N-?4-Aminobutyl?-N-ethylisoluminol?ABEI?as ECL luminopHore,a new signal tag was acheived according to the assembly of ABEI functionalized Ag NPs?ABEI-Ag?on the CoS NFs via Ag-S bond,which integrated with the ECL luminopHore and bis-co-reaction accelerator.In addition,to fabricate sensing interface,primary antibodies?Ab1?was immobilized on the glassy carbon electrode which decorated with Au nanoparticles?Au NPs?,almost providing a zero background signal.As a result,this developed biosensor for cTnT possessed a linear range from 0.1 fg mL^-11 to 100 pg m L^-1and limit of detection down to 0.03 fg mL^-1.2.Based on the SQDs-MOFs compounds for fluorescence sensor constructionpH is one of the most important pHysical and chemical parameters of aqueous solutions,and it is also an important parameter of pHysiological activity,chemical reaction and water environment.In general,abnormal pH changes usually indicate the occurrence of diseases such as the production of a disease,the failure of a chemical reaction,or the pollution of a water environment.Therefore,pH monitoring has always been one of the core tasks in the fields of industrial production,biomedicine and environmental protection.In the detection of pH value,although commonly used pH test papers and pH meters are easy to use,they have the problems of low sensitivity and poor effect,and cannot be used in biological systems.Through the development of fluorescent probe research,pH fluorescence detection methods have attracted wide attention.Among them,the most researched are fluorescent pH sensors based on fluorescent molecules or nanocrystals.Since most fluorescein molecules are modified on the surface,the stability and repeatability of the sensor are also poor.In this paper,sulfur quantum dots?SQDs?and metal organic framework compounds?MOFs?were selected to synthesize SQDs-MOFs composites by hydrothermal recombination.Compared with SQDs,the composite material has enhanced stability;compared with MOFs,its nano-flower-like structure has a larger specific surface area.The fluorescent pH sensor constructed based on SQDs-MOFs exhibits good sensitivity and selectivity.The detectable pH range is 3.8-10.9,and its stability has been greatly improved.3.Based on the SQDs-MOFs compounds for electrochemiluminescence sensor constructionAs an important semiconductor nanomaterial,quantum dots are also very popular ECL materials.However,semiconductor quantum dots are often biologically toxic,which increases the difficulty of their clinical application in biology.Based on this,sulfur quantum dots have been proposed,and the application range of quantum dots has been greatly improved.However,SQDs cannot be stable for a long time in an acid environment.In this work,we changed the ratio of SQDs and MOFs to prepare the cubic structure of SQDs-MOFs composite nanomaterials.The material can be stable for a long time in an acidic environment,and compared with SQDs in a free state,this aggregated SQDs-MOFs exhibit a significantly enhanced ECL response in aqueous solution.Therefore,we built an ECL sensor based on SQDs-MOFs for pH detection.The sensor has an ideal linear response in the concentration range of 5.2 to 9.7,and the reusability of the sensor has been greatly improved.