title: Development of gold nanoparticle-sheathed glass capillary nanoelectrodes for sensitive detection of cerebral dopamine.
abstract: To develop in vivo monitoring strategies of neurotransmitters involved in brain chemistry is a challenging work for progress in understanding the roles that biomolecules play in pathology and physiology. Here we report a new type of gold nanoparticle-sheathed glass capillary nanoelectrode (Au/GCNE) for sensing cerebral dopamine. First, a size-controlled needle-type quartz capillary was pulled with a laser puller. Then, the capillary tip exterior was chemically functionalized with colloidal gold nanoparticles by the seed-mediated growth protocol. Through insulating the above tip with cathodic electrophoretic paint followed by heating to tune the exposed area of gold-nanoparticle-film, the Au/GCNE with tip apex radius ranging from ~8.9 to ~500 nm can be prepared. Scanning electron microscopy (SEM) and steady-state voltammetry were utilized to characterize the effective radius of nanoelectrodes. The results showed that the tip apex radius of Au/GCNE was mainly affected by the pre-pulled capillary tip, the modified AuNPs and the cathodic electrophoretic paint. By taking advantage of the modified AuNPs and the enhanced electrochemical performance of the nanoelectrode, a wide dynamic linear range from 2.0×10(-8) M to 5.6×10(-6) M with a low detection limit of 1.0×10(-8) M (S/N=3), as well as good selectivity for dopamine, were first achieved with the Nafion-modified Au/GCNE. In addition, the designed glass substrates of Au/GCNE were mechanically stronger and their sharp tips aided in membrane penetration during implantation in the in vivo experiment. As a result, the Nafion-modified Au/GCNE was successfully applied for amperometrically monitoring dopamine in the striatum of anesthetic rats.
authors.affiliation: Department of Chemistry, East China Normal University, 500 Dongchuan Road, Shanghai 200241, PR China.
authors.forename: Yingzi
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Department of Chemistry, East China Normal University, 500 Dongchuan Road, Shanghai 200241, PR China.
authors.forename: Qianqian
authors.initials: Q
authors.lastname: Yao
authors.affiliation: Department of Chemistry, East China Normal University, 500 Dongchuan Road, Shanghai 200241, PR China.
authors.forename: Xiaomeng
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Department of Chemistry, East China Normal University, 500 Dongchuan Road, Shanghai 200241, PR China.
authors.forename: Meina
authors.initials: M
authors.lastname: Li
authors.affiliation: Department of Chemistry, East China Normal University, 500 Dongchuan Road, Shanghai 200241, PR China. Electronic address: awzhu@chem.ecnu.edu.cn.
authors.forename: Anwei
authors.initials: A
authors.lastname: Zhu
authors.affiliation: Department of Chemistry, East China Normal University, 500 Dongchuan Road, Shanghai 200241, PR China. Electronic address: gyshi@chem.ecnu.edu.cn.
authors.forename: Guoyue
authors.initials: G
authors.lastname: Shi
mesh_terms: D000818:Animals; D060166:Capillary Tubing; D003217:Conductometry / Q000295:instrumentation*; D003342:Corpus Striatum / Q000378:metabolism*; D004298:Dopamine / Q000032:analysis / Q000378:metabolism*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005898:Glass / Q000737:chemistry; D006046:Gold / Q000737:chemistry; D008297:Male; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D008832:Microchemistry / Q000295:instrumentation; D008839:Microelectrodes; D051381:Rats; D017207:Rats, Sprague-Dawley; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D006046:Gold; D004298:Dopamine
keywords: Dopamine; Gold nanoparticle; Nanoelectrode; Quartz glass capillary; Rat brain