Solutions of Glu (40 mM-4.0 μM), Fru (0.4 mM), Gal (0.4 mM) and Man (0.4 mM) in deionized water were prepared. An aliquot (2.0 mL) of the solution of TPEDB (0.1 mM) in the carbonate buffer containing 4 vol % DMSO was added into a 10 mL volumetric flask, followed by the addition of 1.0 mL of a solution of Fru (0.4 mM) and 1.0 mL of a solution of Glu (40 mM). After shaking for a few seconds, a solution of TPEDB (50 μM) with 10 mM of Glu and 0.1 mM of Fru in the carbonate buffer containing 2% DMSO was obtained. The solution was allowed to stand for 30 min before its FL measurement. The solution of TPEDB and Glu containing another saccharide (Gal or Man) was prepared by similar procedures.
