Preparation Of Vertical/Horizontal Growth Graphene Microelectrodes And Their Presence In Dopamine,Serotonin And Tryptophan Application In Detection

The development of microelectrodes for in situ rapid detection of neurotransmitters and their metabolic levels in human biological fluids is of great significance in biomedical research.In this work,self-supported graphene microelectrodes(VG/HG)are fabricated for the quantification of dopamine(DA),serotonin(5-HT),and tryptophan(Trp).These graphene microelectrodes are prepared by growing B,N,and co-doped vertical graphene nanosheets(VG)on horizontally grown graphene(HG)microelectrodes.By investigating the influences of B and N atoms and VG layer thickness on the response current of neurotransmitters,the high electrocatalytic activity of BVG/HG on monoamine compounds is explored.In the quantitative analysis using the BVG/HG electrode,the linear concentration ranges are 1-400 μM for DA and 1-350 μM for 5-HT,with a pH 7.4 environmental close to the blood.The limits of detection(LODs)of DA and 5-HT are 0.271 and0.361 μM,respectively.For Trp,the sensor has a wide linear range of 3(or 5)-1500μM in a wide pH range of 5.0-9.0,with the LOD fluctuates in the 0.58-1.04 μM range.The VG/HG electrodes are reported for the first time and the fabricated BVG/HG-based sensor is suitable for the determination of DA,5-HT,and Trp in human blood and intestinal secretion samples.