The Analytical Application Of Ru（bpy）₃²⁺ Derivatives In Electrochemiluminescence And Luminescence Probe

Ru(bpy)32+and its derivatives have been widely applied in various fields of analytical chemistry due to it has some excellent features, such as oxidation-reductiion reversibility, optical stability, larger stokes displacement and moderate fluroescence quantum yield. The application of Ru(bpy)32+derivatives in electrochemiluminescence and fluorescence detection has been studied in this paper.First, electrochemiluminescence (ECL) of bimetallic ruthenium tris-bipyridyl complex [(bpy)2Ru(bpy)(CH2)8(bpy)Ru(bpy)2]4+at glass carbon (GC) electrode has been employed for the determination of the most commonly used four quinolone antibiotics. It gave a linear response over a concentra range of1.0×10-13-1.0×10-6mol/L,1.0×10-14-1.0x10-7mol/L.1.0x10-15-1.0×10-6mol/L and1.0×10-15-1.0×10-6mo]/L for ofloxacin. levofloxacin, norfloxacin and ciprofloxacin, respectively. A remarkable detection limit of1.0x10-13mol/L,1.0x10-14mol/L,1.0x10-15mol/L and1.0x10-15mol/L can be reached for ofloxacin, levofloxacin, norfloxacin and ciprofloxacin in0.10mol/L phosphate buffer. Which is much lower than other detection methods. To check its applicability, the proposed method was employed to the determination of ofloxacin, levofloxacin, norfloxacin and ciprofloxacin added into a milk sample respectively, and good reproducibility and stability were achieved. All these provide a possibility to develop an ECL detection method for quinolone antibiotics residues.Second, the ECL of [Ru(bpy)2dppz]2+was investigated and applied to study the interaction of [Ru(bpy)2dppz]2+with DNA. ECL of [Ru(bpy)2dppz]2+-TPrA is negligible in aqueous solution, and increases-200times when [Ru(bpy)2dppz]2+intercalates into the nucleic acid structure. Under optimal conditions, it gave a linear response over a concentra range of1.0x10-9×10-5mol/L for CT-DNA. A remarkable detection limit of1.0×10-9mol/L can be reached for CT-DNA in0.10mol/L phosphate buffer (pH=7).Finally, a rapid and highly selective fluorescence probe has been developed to determine the in vitro and in vivo ClO-/H2S redox cycle using a ruthenium tris-bipyridyl complex covalently linked with phenothiazine. The fluorescence intensity was considerably enhanced upon the addition of CIO-due to the oxidation of the probe to its sulfoxide derivative, which quickly returned to the original level by the reaction with H2S due to the reconstitution of the probe. The redox cycle can be repeated at least12times. Under optimal conditions, the fluorescence intensities are linear over the concentration range1.0x109-1.0x10-4mol/L for ClO-and1.0x10-9-1.0x10-4mol/L for H2S, and the detection limits are1.8x10-11mol/L for ClO-and1.2x10-11mol/L for H2S, which are much lower than those obtained with other detection methods. The proposed method is simple in design and fast in operation, and is suitable for the reversible determination of ClO-and H2S in vitro and in vivo with high selectivity.