Electrochemical Enrichment And Raman Spectroscopy Detection Of Dopamine And 5-Hydroxytryptamine By Gold Nanoelectrode

Simultaneous detection of small molecule neurotransmitters dopamine (DA) and 5-hydroxytryptamine (5-HT) has become a research hotpot in the field of life sciences. A single electrochemical detection mean is difficult to accurately identify analytes. Therefore, it is particularly important for the multimode simultaneous detection and analysis. In this study, a dual-functional gold nanoelectrode-nanopipette based on the nanopipette was constructed with electrochemical properties and Raman activity. On the basis of the carbon nanoelectrode-nanopipette, the apex of it deposited gold by electrochemistry and then enriched analytes by dielectrophoresis (DEP) method, which could be used for the detection of DA and 5-HT in low concentration. The results showed that this nanoelectrode achieved the enhanced electrochemical responses and differentiated the two. The introduced silver nanoparticles (AgNPs) were used as Raman enhancement factor and as the nanoparticles of analytes capturer. By utilizing DEP enrichment method, the Raman signal was enhanced by two orders of magnitude and the characteristic peaks of DA and 5-HT in the mixture were identified. When this nanoelectrode was applied in the analysis of serum samples, as the number of enrichment reached up to the third time, the enhanced electrochemical response could also be obtained, but this response was limited by the number of enrichments.