In this work, a novel long-wavelength fluorescence probe, 3-(4-chloro-6-methylamino-1,3,5-triazinylamino)-7-dimethylamino-2-methylphenazine, was synthesized by the reaction of neutral red and methylamine subsequently with cyanuric chloride, and its recognition behavior for thymine together with its spectroscopic properties in different solvents was studied. The results show that the fluorescence probe can be selectively quenched by thymine instead of guanine, suggesting that the fully complementary hydrogen bonding plays a key role in such a recognition process.
The synthesis of a novel long-wavelength fluorescent probe, 3-epoxypropoxy fluorescein, and its properties for labeling of histidine are briefly described in this communication. The probe is highly selective for histidine, and other amino acids with a concentration of 1 000 times higher than that of histidine did not show noticeable interferences. As an application of this probe, fluorescent labeling of histidine in human serum was attempted and the obtained results were in agreement with those given by using histidine-nickel complex adsorptive voltammetry, both of which were within the normal range of the results reported in literatures.
