Imaging Neurotransmitters In Vivo Using Functionalized Carbon Nanotubes

Abstract

Imaging based detection of changes in extracellular neurotransmitter concentration in living tissue is achieved using novel nanotube-based sensors. The sensors are functionalized, neurocompatible single-walled carbon nanotubes (SWNT) comprising an adsorbed neurotransmitter analyte selective polynucleotide.

1 . A functionalized, neurocompatible single-walled carbon nanotube (SWNT) comprising an adsorbed neurotransmitter analyte selective polynucleotide covalently bound to a neurocompatible polyethyleneglycol (PEG). 
     
     
         2 . The nanotube of  claim 1  wherein the polynucleotide is ssDNA or ssRNA 
     
     
         3 . The nanotube of  claim 1  wherein the polynucleotide has a periodic purine-pyrimidine pattern. 
     
     
         4 . The nanotube of  claim 1  wherein the polynucleotide is ssDNA or ssRNA; and
 the polynucleotide has a periodic purine-pyrimidine pattern. 
 
     
     
         5 . The nanotube of  claim 1  wherein the polynucleotide is ssDNA or ssRNA; and
 the polynucleotide is polyGT is (GT)n, wherein n is an integer 4-30. 
 
     
     
         6 . The nanotube of  claim 1  wherein the polynucleotide is ssDNA or ssRNA; and
 the polynucleotide is polyGT is (GT)n, wherein n is 6. 
 
     
     
         7 . The nanotube of  claim 1  wherein the analyte is a neurotransmitter selected from a catecholamine (e.g. epinephrine (adrenaline), norepinephrine (noradrenaline), and dopamine), histamine, 5-hydroxytryptamine (serotonin), γ-aminobutyric acid (GABA), glutamine, glutamic acid or a neurotransmitter metabolite selected from L-3,4-dihydroxyphenylalanine (L-dopa), 3,4-Dihydroxyphenylacetic acid (DOPAC), homovannilic acid and tyramine 
     
     
         8 . The nanotube of  claim 1  wherein the analyte is dopamine. 
     
     
         9 . The nanotube of  claim 1  wherein the PEG is PEG MW 400-20000. 
     
     
         10 . The nanotube of  claim 1  wherein the analyte is dopamine; and
 the PEG is PEG MW 400-20000. 
 
     
     
         11 . The nanotube of  claim 2  wherein the analyte is dopamine; and
 the PEG is PEG MW 400-20000. 
 
     
     
         12 . The nanotube of  claim 3  wherein the analyte is dopamine; and
 the PEG is PEG MW 400-20000. 
 
     
     
         13 . The nanotube of  claim 4  wherein the analyte is dopamine; and
 the PEG is PEG MW 400-20000. 
 
     
     
         14 . The nanotube of  claim 5  wherein the analyte is dopamine; and
 the PEG is PEG MW 400-20000. 
 
     
     
         15 . The nanotube of  claim 6  wherein the analyte is dopamine; and
 the PEG is PEG MW 400-20000. 
 
     
     
         16 . A functionalized, neurocompatible single-walled carbon nanotube (SWNT) comprising an adsorbed dopamine-selective polynucleotide of sequence (GT) 6 . 
     
     
         17 . The nanotube of  claim 16  wherein the polynucleotide is covalently bound to a neurocompatible polyethyleneglycol (PEG). 
     
     
         18 . The nanotube of claiml 6  wherein the PEG is PEG MW 400-20000. 
     
     
         19 . The nanotube of  claim 16  wherein the polynucleotide is covalently bound to a neurocompatible polyethyleneglycol (PEG); and
 the PEG is PEG MW 400-20000. 
 
     
     
         20 . A method of imaging comprising: detecting changes in extracellular neurotransmitter concentration with the nanotube of  claim 1  wherein the changes in extracellular neurotransmitter concentration are detected in neural tissue, and the nanotube is delivered to and/or located in live brain tissue in a brain slice or live mammal.