Patent Document ID: 9862697
Application ID: 14449672
Patent Flag: 1

Claim One:
1. A fluorescence sensing compound for detecting and visualizing a synaptic release of one or more primary amine neurotransmitters, the fluorescence sensing compound having the following formula: wherein: the sulfamidyl group at the C7-position is an electron-donor that confers an internal charge transfer mechanism to the compound upon deprotonation, which occurs at a pH that is between that of a synaptic vesicle and that of a synaptic cleft; the aldehyde group at the C3-position is an electron-acceptor and enables an iminium-ion formation with said primary amine neurotransmitter(s); R 1 and R 2 are each independently selected from the group consisting of hydrogen, alkyl, alkylene, aryl, and cycloakyl; R 3 is selected from the group consisting of hydrogen, alkyl, alkylene, aryl, and cycloakyl; and the fluorescence sensing compound has a pK a that is in a range of 6.0 to 7.4.