Monosaccharide optical sensor based on ruthenium(II)-bis(bipyridine) of 4-nitrophenyl-di-2-pyridyl ketone hydrazone (dpknph), [Ru(bipy)2(dpknph)]Cl2

Optical measurements on [Ru(bipy)2(dpknph)]Cl2, where bipy is 2,2′-bipyridine and dpknph is di-2-pyridyl ketone p-nitrophenyl hydrazone, in polar dimethyl sulfoxide (DMSO) in the presence and absence of NaBH4/NaBF4 confirmed the reversible interconversion between the high- and low-energy electronic states of [Ru(bipy)2(dpknph)]Cl2 at 576 and 412 nm, respectively. The addition of an external stimulus improves the optosensing behavior of [Ru(bipy)2(dpknph)]Cl2 because of the disturbance of the equilibrium distribution of the electronic states. Optical measurements on [Ru(bipy)2(dpknph)]Cl2 in the presence and absence of NaBH4 reveal high sensitivity of the electronic states of [Ru(bipy)2(dpknph)]Cl2 to slight variations in the concentration of monosaccharide, glucose and fructose in this study. Monosaccharide in concentration as low as 1×10−9 M can be detected and determined using [Ru(bipy)2(dpknph)]Cl2 in DMSO in the presence and absence of NaBH4. In the presence of NaBH4, the system shows higher sensitivity toward glucose.