Detection of Neurotransmitters Via Quantum Dots

Abstract

Quantum dots have been used for the detection of gamma amino butyric acid (GABA), one of chief inhibitory neurotransmitters. Quantum dots (QDs) with carboxyl functional group have been covalently bonded to goat anti-rabbit IgG labeled with Alexa Fluor, and their fluorescence spectra change has been studied. By addition of Alexa Fluor, immunocomplex was formed and the local distance between QD and Alexa Fluor became closer and fluorescence resonance energy transfer (FRET) process from QDs to dyes could be observed. The FRET efficiency was obtained based on their spectra intensity ratio, and this was further confirmed by the lifetime measurement. By addition of rabbit polyclonal with GABA, the FRET efficiency was decreased which means the local distance between QDs and Alexa Flour was increased. The dependence of FRET efficiency on GABA concentration shows that QDs combined with fluorescent dyes can be used for the detection of neurotransmitters.