Nitric Oxide-adsorbed Functional Poiymer Prepared By Regulation And Controll Of Molecular Imprinting And Its Electroanalvtical Characteristics

In this paper, an imprinted polymer, P-1[CoII(salen)](salen: bis(2-hydroxy-benzaldehyde)ethylenediimine), was firstly synthesized and characterized by Fourier transform infrared(FT-IR) analysis, thermogravimetric analysis (TGA) and differential scanning calorimetry(DSC). GC-MS was used to investigate the specific binding thermodynamics, kinetics, andselective recognition of P-1[CoII(salen)] to nitric oxide (NO). This study on binding kineticsindicates that the binding of the polymer to NO fits the first-order kinetics with a rate constantk1of0.0867min-1(r2=0.980, χ2=0.0113). Langmuir and Freundlich equations were used toexplain the equilibrium character of P-1[CoII(salen)] binding to NO and the r2(0.999) and χ2(0.355) values of the Langmuir equation suggestted that total NO binding by P-1[CoII(salen)]can be best fitted by the Langmuir equation. The maximum binding capacity (Bmax) ofP-1[CoII(salen)] was calculated to be76.28μmol/g, very similar to the experimental value,75μmol/g. The selective experiment showed that the affinity of P-1[CoII(salen)] to NO wasmuch higher than carbon dioxide (CO2) and oxygen (O2), suggesting that P-1[CoII(salen)] is apromising functional material for NO-storage.A novel amperometric NO sensor was prepared by modifying an imprinted functionalpolymer P-1[CoII(salen)] on the surface of a glassy carbon electrode (GCE) with the help ofmulti-wall carbon nanotubes (MWCNTs) and chitosan (CS), in which P-1[CoII(salen)]worked as an artificial recognition receptor for NO, but was not a traditional molecularlyimprinted polymer, in that the template molecule was not used to develop binding sites withenhanced affinity and selectivity towards the template molecule. The analytical performancesof the NO sensor were characterized by differential pulse voltammetry (DPV) andamperometric measurements (i–t). The experimental results indicated that the developedsensor exhibited an excellent selectivity, long-term stability, high sensitivity, goodreproducibility, excellent anti-interference ability with the NO concentration in the range of7.2×109–9.0×105mol/L and the detection limit of2.99×109mol/L (S/N=3). Finally,the sensor was successfully applied to the detection of NO release from peach fruits. Thus, thecurrently developed NO sensor is applicable in quantitative detection NO in manybiological/physiological systems and has great potential in further understanding theoreticalfundamentals of unknown NO-related processes.