Neurotransmitters are important chemicals in human physiological systems for initiating neuronal signaling pathways and in various critical health illnesses. However, concentration of neurotransmitters in the human body is very low (nM or pM level) and it is extremely difficult to detect the fluctuation of their concentrations in patients using existing electrochemical biosensors. In this work, we report the performance of highly densified carbon nanotubes fiber (HD-CNTf) crosssections called rods (diameter ∼ 69 μm, and length ∼ 40 μm) as an ultrasensitive platform for detection of common neurotransmitters. HD-CNTf rods microelectrodes have open-ended CNTs exposed at the interface with electrolytes and cells and display a low impedance value, i.e., 1050 Ω. Their fabrication starts with dry spun CNT fibers that are encapsulated in an insulating polymer to preserve their structure and alignment. Arrays of HD-CNTf rods microelectrodes were applied to detect neurotransmitters, i.e., dopamine (DA), serotonin (5-HT), epinephrine (Epn), and norepinephrine (Norepn), using square wave voltammetry (SWV) and cyclic voltammetry (CV). They demonstrate good linearity in a broad linear range (1 nM to 100 μM) with an excellent limit of detection, i.e., 32 pM, 31 pM, 64 pM, and 9 pM for DA, 5-HT, Epn, and Norepn, respectively. To demonstrate practical application of HD-CNTf rod arrays, detection of DA in human biological fluids and real time monitoring of DA release from living pheochromocytoma (PC12) cells were performed.

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A new dmucleating SchifT base ligand HL(L=C~~HITNZO;) hss been eyntheeised and characterized. The single crystal structure of its complex [LzCtuO(Ac0~)].2HzO has been determined by X-ray dfiaction methods. The reault indicated that every Cu atom has its square pyramidal coordination polyhedron and there is a tetrahedral C u r 0 core in the complex molecule.Its active siten where catalytic oxidation of dioxygen occurs have been inferred. KeywordrPolynuclear complex, SchifT base, crystal structure .. \OHor both atoms of dioxygen into an organic substrate where dioxygen serves as an election sink in the oxidation.2 A number of polynuclear complexes have therefore been reported and studied as models of metal-metal interaction and redox catalysis. Schiff base condensation of 2,6-diformyl-4-methylphenol(dfp) and various primary amine compounds produced corresponding macrocycle or open-chain ligands.So far as acyclic end-off conjugate ligands containing end hydroxy groups were concerned, the dinuclear copper(I1) complex of L' was studied at And the structure of the mixed oxide state Co(I1)-Co(II1) complex of L' which shows a dimer

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