Research On Silver Nanoclusters And Carbon Dots Based Light-Addressable Biochemical Sensors For Multichannel Detections Of Dopamine And Glutathione And Its Applications In Diagnosis Of Parkinson's Diseases

With the aging of the population,the number of Parkinson's disease?PD?patients is increasing quickly,and the PD seriously threatens health and life quality of people.Therefore,it is particularly important to diagnose and treat PD timely and accurately.PD,as a common neurological disease caused by the degeneration of nerve cells,can cause damage to dopaminergic neurons,which directly leads to the decrease of dopamine?DA?in patients.Therefore,PD can be diagnosed by high-sensitive detection of DA.Meanwhile,glutathione?GSH?,as an important antioxidant in the brain,also has a closely relationship with the damage of dopaminergic neurons,which also causes the decrease of GSH in patients.The high-sensitive detection of GSH can provide more information about PD,which helps to improve the accuracy of PD diagnosis.Therefore,high-sensitive detections of DA and GSH can diagnosis PD more accurately and comprehensively.In this research,light-addressable biochemical sensors were developed for the multichannel detections of DA and GSH with high sensitivity and good selectivity.First,to achieved DA detection,Ag₄₄?SR?₃₀silver nanoclusters?AgNCs?with 5-mercapto-2-nitrobenzoic acid?MNBA?ligands were synthesized.And the AgNCs based photoelectrochemical?PEC?sensors were developed for high-sensitive and selective DA detection for the first time.The graphene oxide?GO?and silver nanoparticles?AgNPs?were introduced into AgNCs to construct hybrid nanomaterials to further improve the sensing properties towards DA.According to the experimental results,the introduction of AgNPs and GO significantly improved the sensing properties of the sensors towards DA.The AgNCs/AgNPs/GO based PEC sensors achieved high sensitivity?7.476 n A/?M?and low limit of detection?LOD,53n M?in the linear range of 0.16-6?M DA concentration,which indicates that the high-sensitive detection for DA was achieved.Second,carbon dots?CDs?based PEC sensors were fabricated,and high sensitivity?21.79 n A/?M?and good LOD?34.3 n M?were achieved in the linear range of 0.1-1?M GSH concentration.Third,AgNCs/AgNPs/GO and CDs sensors were combined and extended into light-addressable sensors for multichannel detections of DA and GSH.The algorithms were used to reduce interferences between analytes,and the accurate concentrations of DA and GSH in the mixed solution were obtained.Finally,to verify the practicability of our designed light-addressable sensors,the PD biological model samples from mice were measured by light-addressable sensors and commercially available detection kits.The relationships between the DA and GSH concentration and the PD stage were proved.Compared with available detection kits,the designed light-addressable sensors showed better stability and lower limit of quantitation?LOQ?.The developed light-addressable sensors not only have the advantages of high sensitivity,fast response,simple operation and multichannel detection,but also can be expanded to detect more biological molecules related to PD,which can provide more information about PD and improve the accuracy of PD diagnosis.