Internal Environment of Agarose Gel Studied by the ESR Spectroscopy

Abstract

PVA-TEMPO as a polymer spin reagent was synthesized from poly(vinyl alcohol) (PVA) and 4-(2-chloroacetamido)-2,2,6,6-tetramethylpiperidine 1-oxyl (4-2C-TEMPO). PVA-TEMPO was doped into agarose gel. When the PVA-TEMPO-doped agarose gel was measured by ESR spectroscopy, the molecular motion of PVA-TEMPO found to be slower than the PVA-TEMPO aqueous solution in the temperature range from 7 to 60°C. On the other hand, PEG-TEMPO, which was synthesized from PEG and 4-2C-TEMPO, was doped into agarose gel. When the PEG-TEMPO-doped agarose gel was measured by ESR spectroscopy, no differences in molecular motion of PEG-TEMPO between in the PEG-TEMPO-doped agarose gel and in the PEG-TEMPO aqueous solution were recognized in the temperature range from 7 to 60°C. In this article, we discuss the internal environment of agarose gel from the ESR spectroscopy and the FT-IR spectroscopy results.