||Identification and quantification of oxide functional groups including aldehyde/ketone carbonyls, carboxylic acids, and hydroxyl groups on the surface of herringbone graphitic nanofibers (GNFs) was carried out using FLOSS (the Fluorescent Labeling of Surface Species). Of the carbon atoms on the surface of nitric acid oxidized herringbone GNFs a total of 2.5% were found to bear oxide functionality. Aldehyds and ketones comprised 0.9% of surface carbon, carboxylic acids comprised between 1.0 and 1.5% of surface carbon, and hydroxyl groups were found on 0.4% of surface carbon. As-produce and demineralized herringbone GNFs contained much lower levels of oxygen bearing functionality with no more than 0.3% and 0.05% of surface carbon as aldehyde/ketone carbonyls respectively. The knowledge of oxide functional group density on the surface of the GNFs through the covalent attachment of fluorescent dyes will guide future efforts to covalently functionalize the GNFs with complicated ligands such as carbohydrates.