In situ characterization of surface physicochemical properties of carbon nanofibers using 1-naphthol as a fluorescent probe

Design and Evaluation of Naphthol- and Carbazole-Containing Fluorescent σ Ligands as Potential Probes for Receptor Binding Studies

Some 3,3-dimethyl-1-(3-naphthylpropyl)piperidine and 1-cyclohexyl-4-(3-naphthylpropyl)piperazine derivatives, structurally containing naphthol as a fluorescent moiety, were prepared for being potentially used as fluorescent sigma ligands. Structurally related analogs were also prepared, where the naphthalene nucleus was replaced by the fluorescent carbazole moiety and chain length was varied. For all compounds the in vitro affinities toward sigma receptors and Delta8-Delta7 sterol isomerase site were measured, and the fluorescent properties were determined. Compound 19 gave the best results both for sigma receptor affinities (sigma1, Ki = 6.78 nM and sigma2, Ki = 26.4 nM) and fluorescence features; thus, it was chosen for in vitro saturation binding analysis at sigma receptors. The good results obtained in such assay suggested that the fluorescent compound 19 could be used instead of a radioligand in "green" binding assays.

Dispersion of Acid-Treated Carbon Nanofibers into Gel Matrices Prepared by the Sol−Gel Method

1-Naphthol has been used as an in-situ fluorescent probe to characterize the dispersibility of carbon nanofibers (CNFs) into the sol-gel matrix of silicon alkoxide. The ion-pair fluorescence of 1-naphthol was found in the gel dispersing acid-treated CNFs instead of 1Lb fluorescence, which was preferred in the low polar gel matrix. This indicates that 1-naphthol easily interacts with oxidized groups present on the surface of the acid-treated CNFs due to the high dispersibility of the CNFs into the gel matrix. The oxidized groups on the CNF surface are useful for preventing self-assembly and/or aggregation of the CNFs in the gel matrix.