Research On The Detection Technology Of Neurotransmitters Based On All-Solid-State Ion-Selective Electrodes

Ion-selective electrodes(ISEs)are one kind of electrochemical sensors which can detect the activity or concentration of the analyte in solution through the membrane potential.The relationship between the potential difference and analyte content is in accord with Nernst equation.Compared with conventional ISEs,all-solid-state ISEs replace the internal electrolyte with solid electrolyte.In addition to keeping the inherent characteristics of ISEs,all-solid-state ISEs also haveseveral advantages,such as being free from influence of steady-state primary ion fluxes,convenient maintenance and easy miniaturization,which make all-solid-state ISEs suitable for neurotransmitters detection in vivo.In this thesis,the miniaturized all-solid-state neurotransmitters ISEs and a portable multichannel neurotransmitters detection device were developed.The neurotransmitters detection device combined with neurotransmitters ISEs has realized the detection of acetylcholine and dopamine,which provides the neuroscientists a new detection method of neural experiment in vivo.The chemical characteristics,functional mechanisms and research progresses of the neurotransmitters,such as acetylcholine and dopamine,were reviewed and analyzed.The commonly used in vivo neurotransmitters detection technologies were introduced,especially the research status and characteristics of different detection techniques in the analysis of acetylcholine and dopamine were expounded.Detailed descriptions of theoretical basis,structure,classification and characteristics of ISEs were made.The ionosphere response mechanisms of acetylcholine and dopamineas well as conducting polymer working principles were discussed.The applications and advantages of ISEs in the fields of biological detection and environmental monitoring were also introduced.In view of the disadvantages of current neurotransmitters detection technologies,such as complex operation,high cost and poor real-time performance,a new technique for preparation of neurotransmitters ISEs with convenient operation and high sensitivity was studied.Taking acetylcholine as research object,all-solid-state acetylcholine ISEs with different structures were studied.After trying various fabrication processes and optimizing ISEs' components,the miniature all-solid-state acetylcholine ISEs with gold wire as conducting medium,conducting polymer PEDOT/PSS as solid electrolyte and polymer polyvinyl chloride film containing neutral carrier as sensitive membrane were successfully developed.Based on the research of the acetylcholine ISEs,the miniature all-solid-state dopamine ISEs were alsosuccessfully made after a series of optimization experiments.The detection experiments of acetylcholine and dopamine ISEs were also carried out.The electrode performances,such as detection limit,linear range,selectivity and dynamic response were investigated.The thesis provided a new type of electrochemical sensors for neurotransmitters detection in vivo.Combined with the miniature all-solid-state neurotransmitters ISEs,a portable multichannel neurotransmitter detection system was developed.The detection device which integrated operation,display and data transmission functionswas based on open circuit potential method.It could fulfill the continuous detection of various neurotransmitterswithout the external power supplement.The device was stable and reliable in working performance,simple in operation and accurate in detection results.