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.
