Friday, January 3, 2014

Publication uses AE03 (Fol-PEG-COOH) for neurotransmitter detector development

A recent publication by MIT utilized Polyvivo product AE03 (Folate-PEG-COOH) in support of work towards developing a neurotransmitter detector.  Learn more by reading (Kruss, Sebastian, Markita P. Landry, Emma Vander Ende, Barbara MA Lima, Nigel Forest Reuel, Jingqing Zhang, Justin Nelson, Bin Mu, Andrew J. Hilmer, and Michael S. Strano. "Neurotransmitter Detection Using Corona Phase Molecular Recognition on Fluorescent Single-Walled Carbon Nanotube Sensors." Journal of the American Chemical Society (2013). (http://pubs.acs.org/doi/abs/10.1021/ja410433b)

Abstract

Temporal and spatial changes in neurotransmitter concentrations are central to information processing in neuronal networks. Therefore, biosensors for neurotransmitters are essential tools for neuroscience. Here, we apply a new technique, Corona Phase Molecular Recognition (CoPhMoRe), to identify adsorbed polymer phases on fluorescent single-walled carbon nanotube (SWCNT) that allow for the selective detection of specific neurotransmitters including dopamine. We functionalized and suspended SWCNTs with a library of different polymers (n=30) containing phospholipids, nucleic acids, and amphiphilic polymers to study how neurotransmitters modulate the resulting band-gap, near-infrared (nIR) fluorescence of the SWCNT. We identify several corona phases that enable the selective detection of neurotransmitters. Catecholamines such as dopamine increased the fluorescence of specific single-stranded DNA and RNA wrapped SWCNTs by 58-80 % upon 100 µM dopamine addition dependent on SWCNT chirality (n,m). In solution, the limit of detection was 11 nM (Kd = 433 nM for (GT)15-DNA-SWCNT). Mechanistic studies reveal that this turn-on response is due to an increase in fluorescence quantum yield and not covalent modification of the SWCNT or scavenging of reactive oxygen species. When immobilized on a surface, the fluorescence intensity of single DNA or RNA-wrapped SWCNT is enhanced by a factor of up to 5.39 ± 1.44 whereby fluorescence signals are reversible. Our findings indicate that certain DNA/RNA coronae act as conformational switches on SWCNT, which reversibly modulate SWCNT fluorescence. These findings suggest that our polymer/SWCNT constructs can act as fluorescent neurotransmitter sensors in the tissue-compatible nIR optical window, which may find applications in neuroscience.

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