| as a novel functional materials with outstanding electrical, optical, and magnetic properties as well as photo and chemical stability, associated with the intriguing intramolecular π-π interactions, perylenetetracarboxylic diimides and triphthalocyanines, have been studied to be widely potential application as molecular materials for molecular fluorescent probe, molecular information storage, and electrochemical sensor, etc. recent years, many efforts have been centered on the research of new electrocatalytic materials in sensor researches. 1. Synthesis of an amphiphilic perylene diimide derivative(15C5PDI) and cation-induced self-assembly in solution and langmuir–blodgett filmsThe aggregation behaviors of a novel perylenetetracarboxylic diimide(PDI) derivative, N-(4’-benzo-15-crown-5-ether)-N –hexyl-1,7-di(4-tert-butyl-phenoxy)perylen-3,4;9,10-tetracarboxylic diimide(15C5PDI), has been studied in both solution and Langmuir-Blodgett(LB) films. Dimerization of 15C5 PDI is induced in CHCl3 solution with the present of K+, resulting in the formation the slipped co-facial dimmers, as revealed by absorption and emission spectroscopy. Assemblies of 15C5 PDI molecues were studied in Langmuir and Langmuir–Blodgett films. Surface pressure–area isotherm measurements and the spectroscopic studies indicate that 15C5 PDI molecules adopted the H agreagation mode with a face-to-face configuration and edge-on orientation in Langmuir or LB films. More closely the arrangement of 15C5 PDI has been found in the presence of the K+ in subphase than that in water due to the coordination bonding between 15-crown-5-ether and K+ ions, which has been revealed by the π–A isotherms and the XRD spectra. Atomic force microscopy images of the Langmuir film deposited from both water and the K+ solution revealed uniform belt-like and nanorope morphology, respectively, while the X-ray diffraction studies indicate that the molecules in the solid film packed with high order. Furthermore, the conductivity of the LB films prepared in K+ solution is more than ca. 1 order of magnitude higher than those from water. The present result might be valuable for the design and preparation of PDI-based nano-(opto)electronic devices with good performance due to the close relationship between the molecular ordering and dimensions of nanostructures and the performance of nanodevices. 2. Biomimetic sensors based on triphthalocyanine conjugated with tyrosinase using the LB films technique for antioxidant detectionAmong chemical sensors for detecting catechol, the electrochemical sensors modified by phthalocyanines or bisphthalocyanines have been researched over the past few years. However, triphthalocyanines have been rarely used for sensors till now. Owing to our previous researches about triphthalocyanine complexs, their electrochemical activity and electrochemical stability are excellent. In the present case, the working electrodes modified by heteroleptic tris(phthalocyaninato) europium tripledecker complex Eu2(Pc)[Pc(OPh)8]2 were used as the senser to test catechol for the first time.A novel biosensor for the voltammetric detection of catechol is prepared, in which hybrid lipidic layers consisting of Eu2(Pc)[Pc(OPh)8]2 mixed with stearic acid(SA) incorporated tyrosinase(Tyr) was used as active layer(Eu2(Pc)[Pc(OPh)8]2/SA/Tyr) of the ITO working electrode. The microstructure and morphology of the LB films were characterized by using π–A isotherms curve, UV-vis bsorption spectrum, X-ray diffraction, atomic force microscopy. The results showed that Eu2(Pc)[Pc(OPh)8]2 molecules in both pure and mixed LB films take the same aggregation mode(H-type), and the introduction of stearic acid to LB films has not change the type of aggregation for Eu2(Pc)[Pc(OPh)8]2.Excellent electrocatalytic effect and good biocompatibility of the Eu2Pc[Pc(OPh)8]2/SA/Tyr LB films deposited on ITO electrode, leads to a good linearity in the range from 5.26×10-7 to 2.1×10-4 M for catechol with a squared correlation coefficient of 0.9993, and a detection limit of 6.29×10-8 M(S/N= 3) at oxidation peak, and reduction peak also shows a good linearity in the range from 5.26×10-7 to 1.05×10-4 M for catechol with a squared correlation coefficient of 0.9990, and a detection limit of 1.69×10-7 M(S/N= 3). As a demonstration, this novel biosensor was applied to determine catechol concentrations with higher sensitivity, lower detection limit and great storage stability. 3. Dual-functional sensors based on triphthalocyanine using the LB films techniqueIn the field of chemical sensors for testing caffeic acid, so far only the electrochemical biosensors modified by phthalocyanine or biphthalocyanine have been researched. In the experiment, the working electrode modified by europium triphthalocyanine Eu2[Pc(OPh)8]3 were used as the senser to test caffeic acid and hydrogen peroxide for the first time in order to prepare dual-functional sensor.In the experiment, we have researched the aggregation properties and electrochemical properties of Eu2[Pc(OPh)8]3, which is consist of substituent group of phenol oxygen. Firstly, the pure LB films and mixed LB films of the two substances have been prepared, respectively. The mixed LB films are composed of stearic acid(SA) and metal phthalocyanine. By test methods of π – A isotherms curve, ultraviolet absorption spectrum, atomic force microscopy, X-ray diffraction, the microstructure and morphology of the LB films were characterized. The result shows that Eu2[Pc(OPh)8]3 and is J gathered in LB films, and the stearic acid(SA) can improve film-forming ability rather than change their way of gathering. The working electrode is regarded as sensor to text the caffeic acid and hydrogen peroxide by the way of the cyclic voltammetry. Because of the phthalocyanine metal complexes, significant signals are lamplified, and we can observe significant peaks. When detecting catechol by the DPV of the anodic peak, the low detection limit were 3.14 μM, and the sensitivity were 0.066 μA/μM. When detecting hydrogen peroxide by the DPV of the anodic peak, the low detection limit were 1.52 μM, and the sensitivity were 0.050 μA/μM.This suggests that europium triphthalocyanine has better electrochemical sensor characteristics. |
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