Silver nanoclusters and carbon dots based light-addressable sensors for multichannel detections of dopamine and glutathione and its applications in probing of parkinson's diseases.

Parkinson's disease (PD) is a common neurological disease caused by nerve cells degradation which leads to extremely low level of dopamine (DA) in patients. Therefore, ultrasensitive DA detection is particularly important for the assessment and treatment of Parkinson's patients. In this research, photoelectrochemical (PEC) sensors based on Ag(SR) nanoclusters (AgNCs) with 5-mercapto-2-nitrobenzoic acid (MNBA) ligands were first developed for ultrasensitive and selective detection of DA. Then, hybrid nanomaterials by introducing graphene oxide (GO) and silver nanoparticles (AgNPs) into AgNCs were used to enhance sensing properties. AgNCs/AgNPs/GO based PEC sensors achieved high sensitivity (7.476 nA/μM) and low limit of detection (LOD, S/N = 3, 53 nM) in the linear range 0.16-6 μM DA concentration. Besides DA, PD causes the concentration change of other analytes, such as glutathione (GSH). Multichannel detections of different analytes can provide more information in studying PD. Therefore, carbon dots (CDs) based PEC sensors were designed and achieved high sensing performances on GSH detection. Then, AgNCs/AgNPs/GO and CDs based PEC sensors were combined and extended into light-addressable sensors for multichannel detections of DA and GSH. Algorithms were used to solve interference problems to improve the measurement accuracy of DA and GSH in complex solution. Finally, PD biological model samples from mice were measured by light-addressable sensors. The relationships between the DA and GSH concentration and the PD stage were proved. Our designed light-addressable sensors exhibited advantages of multichannel detection, high sensitivity, fast response and so on. In the future, it can be expanded to detect more biological molecules to provide more information on studying PD.