Learn more about Fragile X Syndrome by Astrocyte cells use adenosine triphosphate (ATP) to transfer signals. This process is suggested as a novel therapeutic target in Fragile X Syndrome (FXS), one of autism’s few known genetic causes. Our aim is to develop a carbon fiber electrode aptamer-based sensor capable of single cell and in vivo measurements of ATP to determine the release mechanism and spatial location of ATP. Aptamers are short nucleotide sequences that select for target analytes and translate binding into an electrochemical signal. Carbon fiber is very robust, enabling sensitive measurements while eliminating background processes like oxygen reduction that plague existing measurements. We are developing the linkage chemistry to covalently attach the aptamer to the carbon surface. Specifically, we have electrochemically grafted several compounds (4-aminobenzoic acid and ethylenediamine) to the surface of glassy carbon electrodes and have found 4-nitrobenzene diazonium is best suited for further development. To test for successful grafting, we have employed the positively charged hexaammineruthenium (III) chloride (RuHex) as a redox reporter. Using cyclic voltammetry, changes in observed peak current caused by electrostatic repulsion of RuHex with the grafted electrode surface report on the grafting’s success. With the attached diazonium, we are now poised to fabricate our aptamer sensors on carbon surfaces. To learn more, visit Justine Lottermoser's project at URCAD 2016!