Preparation And Application Of Graphene-supramolecular Nanocomposites

In this article, the combination between calixarene, pillar[n]arene or Au nanoparticles and graphene nanomaterials studied, designed and prepared a variety of synergistic functional nanomaterials with supramolecular recognition. It is realized to combine organically nanoscience and supramolecular chemistry. Here, the following tasks have been designed and achieved in this theme.(1) P-sulfonatocalix[4]arenes sodium [SCn (n=4,6,8)] with the supramolecular recognition ability self-assembled onto the surface of reduced graphene oxide (RGO), and RGO-SCn (n=4,6,8) nanocomposites were obtained. Meanwhile, the water-dispersity of RGO-SCn nanocomposites were investigated. Then, the interaction mechanism between SCn (n=4,6,8) and GO was investigated. Lastly, Fourier transform infrared spectra, Ultraviolet-visible spectroscopy, thermal gravimetric analysis, contact angle measurement, scanning electron microscope, and electrochemical impedance spectroscopy were used to characterize the component, morphology, performance of RGO-SCn.(2) After RGO-SCn (n=4,6,8) modified glassy carbon electrode (GC), the supramolecular recognition ability of RGO-SCn for the four electroactive molecules [dopamine (DA), uric acid (UA), tryptophan (Trp) and methylene blue (MB)] were investigated though cyclic voltammetry (CV). The result indicated that two components of RGO-SCn both exerted themselves advantages and promoted electrochemical response together and RGO-SCn showed different supramolecular recognition ability. Furthermore, the electrochemical response signals on RGO-SC8/GC, RGO-SC6/GC and RGO-SC4/GC were compared, the size of CV current for the same target molecule in the order was RGO-SC8>RGO-SC6>RGO-SC4in the same conditions. That to say, compared to other two modified GC, for any one of four target molecules, RGO-SC8/GC showed the best supramolecular recognition ability, the highest electrochemical signal and the highest current density. RGO-SC8was used to modify GC to detect DA electrochemically using the differential pulse voltammetry (DPV). The peak current versus the concentration of DA had a good linearity in the range from1×10-8to2.1×10-5mol·L-1. The regression equation was i(mA)=0.0106+0.00957CDA(?M) with a correlation coefficient of R=0.9979,and the detection limit was evaluated to be8×10-9mol·L-11based on3signal-noise ratio. Lastly, research result showed that AA, UA and Trp did not interfere with the determination of DA, which indicates that the RGO-SC8/GC has relative good selectivity for DA. As a result, RGO-SC8nanocomposite is very good electrode modified materials and possess very good electrochemical analysis capability.(3) An amphiphilic amino resorcinarene (T) was modified onto the surface of reduced graphene oxide (RGO) to prepare water-soluble RGO-T. Then, the interaction mechanism between T and GO was investigated detailedly. After RGO-T modified glassy carbon electrode (GC), cyclic voltammetry (CV) behaves of four electroactive molecules [dopamine (DA), uric acid (UA), tryptophan (Trp) and methylene blue (MB)] were investigated systematacially on RGO-T/GC. The result showed electrochemical response to four target molecules was higher than those of RGO/GC and bare GC. Further, as-prepared gold nanoparticles (AuNPs) self-assembled onto the surface of RGO-T through amido groups of T to achieve RGO-T-AuNPs nanocomposites. Similarly, RGO-T-AuNPs were coated onto GC to sense four guest molecules by cyclic voltammetry. Electrochemical results showed that the electrochemical response signal on RGO-T-AuNPs/GC was much stronger than that on RGO-T/GC, which indicated that RGO-T-AuNPs can exert the performance of every components.(4) An amphiphilic pillar[5]arene (AP5) was modified onto the surface of reduced graphene oxide (RGO) to form the water-dispersive RGO-AP5nanocomposite. RGO-AP5were coated onto the glassy carbon electrode (GC) to sense six guest molecules [dopamine (DA),4-acetamidophenol (APAP), uric acid (UA), tryptophan (Trp), methylene blue (MB) and imidacloprid(IDP)] by cyclic voltammetry. Electrochemical results showed that the RGO-AP5could exhibit selective supramolecular recognition and enrichment capability toward guest molecules. As for these molecules being small enough to fit into AP5cavity, the electrochemical response signal on RGO-AP5/GC was stronger than that on RGO/GC and bare GC. Further, as-prepared gold nanoparticles (AuNPs) self-assembled onto the surface of RGO-AP5through amido groups of AP5to achieve RGO-AP5-AuNPs nanocomposites. Similarly, RGO-AP5-AuNPs were coated onto GC to sense six guest molecules by cyclic voltammetry. As for these molecules being small enough to fit into AP5cavity, electrochemical results showed that the electrochemical response signal on RGO-AP5-AuNPs/GC was much stronger than that on RGO-AP5/GC. The result showed that RGO-AP5-AuNPs could exert the performance of every components. Lastly, RGO-AP5-AuNPs showed an outstanding analyzing performance for DA with broad linear range (1.5×10-8to1.9×10-5M), good linear correlation (R=0.9973) and low detection limit (1.2×10-8M) at a signal-to-noise ratio of3.