ABSTRACT
A facile colorimetric sensing method for biothiols was developed, based on photocatalytic property of metal-organic frameworks (MOFs), UiO-66(NH2) nanoparticles (NPs), as peroxidase mimics under light irradiation. By the irradiation of a light emitting diode (LED) source, the colorless chromogenic substrate, 3,3',5,5'-tetramethylbenzydine (TMB), was oxidized into blue oxTMB with the aid of the catalytic UiO-66(NH2) NPs. With the existence of biothiols, the oxidization was prohibited, with the blue color paled and absorbance intensity decreased with the concentration of biothiols in a linear manner. Real samples of cysteine, glutathione, and homocysteine were analyzed under the optimized conditions, with high sensitivity (the limit of detection was calculated as 306nM, 310nM, and 330nm respectively) and selectivity. The recovery ranged from 93% to 107% with good precisions (RSD%≤5%). This photocatalytic property of UiO-66(NH2) as peroxidase mimics was studied based on steady-state kinetics, and the mechanism of oxidization process was also briefly discussed. This developed MOFs-based colorimetric sensing method demonstrated advantages over others for biothiols sensing, including high photo-catalytic activity compared to other nanomaterials, oxidation without H2O2, ease of regulation with the LED source, and low cost without expensive instrument and technically demanding.
Subject(s)
Coordination Complexes/chemistry , Metal Nanoparticles/chemistry , Sulfhydryl Compounds/analysis , Zirconium/chemistry , Benzidines/chemistry , Benzidines/radiation effects , Catalysis , Colorimetry , Coordination Complexes/radiation effects , Light , Metal Nanoparticles/radiation effects , Peroxidases , Photochemical Processes , Sulfhydryl Compounds/chemistry , Zirconium/radiation effectsABSTRACT
2D microstructures of N,N'-diphenyl-N,N'-bis(1-naphthyl)-1,1'-biphenyl-4,4'-di-amine (NPB) have been prepared by a facile solution method and fully characterized. The as-prepared NPB microsheets have well-defined shapes and very smooth surfaces, and are ideal building blocks for 2D optical waveguides. The results indicate that the optic losses within NPB microsheets are closely related to the direction of propagation, and the shape of microsheets can change the direction of waveguiding light. Such 2D optical waveguides may have potential applications in future miniaturized light-based circuits serve as interconnectors different from 1 D optical waveguides.