| Responsive polymer materials can adapt to surrounding environments, regulate transport of ions and molecules, change wettability and adhesion of different species on external stimuli, or convert chemical and biochemical signals into optical, electrical, thermal and mechanical signals, and vice versa. These materials are playing an increasingly important part in a diverse range of applications, such as drug delivery, diagnostics, tissue engineering and ’smart’ optical systems, as well as biosensors, microelectromechanical systems, coatings and textiles. Due to the remarkable advantages of molecular devices, such small-size, facile synthesis and easy structural modifications, large storage, fast response, artificial intelligence, ete., the study of molecular devices has become one of the most important research areas arising from multi-discipline subjects(Chemistry, Physics, and Materials, Science). So this paper focuses on stimuli-responsive macromolecular nanostructures that are capable of conformational and chemical changes on receiving an external signal. These changes are accompanied by variations in the physical properties of the polymer. We also design the biomolecular-based logic gates and its detection of organophosphorus pesticides. The major contents are as follows:1. The graphene oxide and graphene were successful synthesis based on Hummers’method. And then the poly N-isopropylacrylamide grafted surface graphene nanosheets to be temperature-sensitive graphene nanosheets composites by radical polymerization method. The PNIPAm-graphene composite material was successfully characterized using UV-visible absorption spectroscopy (UV-Vis), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and electrochemical methods. The lower critical solution temperature (LCST) of PNIPAAm was measured to be33℃. When the PNIPAm gels were grafted to graphene the resultant composites were also thermosensitive in aqueous solutions exhibiting a reversible suspension behavior at28℃. The hydrophilic/hydrophobic property of PNIPAm-rGO can change structure quickly from the hydrated state below the LCST to the dehydrated state above the LCST and that the structural change of the PNIPAm-rGO in the heating and cooling circle is reversible. The resurts also demonstrate that the electron transfer ON/OFF switch behavior of the PNIPAm-rGO-modified interface.2. The new thermo-responsive poly-N-isopropylacrylamide/Au nanoparticles (PNIPAm/Au NPs) and poly (acrylic acid)/Au nanoparticles (PAA/Au NPs) films were synthesized and characterized. Thioaniline-functionalized Au nanoparticles were first electropolymerized on a thioaniline monolayer-modified Au electrode to create a three-dimensional bis-aniline-cross-linked Au nanoparticle composite. Then PNIPAm and PAA hydrogels were fabricated by cycling an electronic potential in aqueous solution, respectively. These PNIPAm/Au NPs and PAA/Au NPs composites films exhibited excellent hydrophilic/hydrophobic and electrochemical reversibility. The control of the surface micro-/nanostructure and the chemical composition is critical for these hydrophilic/hydrophobic properties. These surfaces with controllable wettability are of great importance for both fundamental research and practical applications.3. The enzymatic systems which involve biocatalytic reactions utilized for information processing (biocomputing) was constructed. In the experiments, the acetylcholine esterase (AChE), choline oxidase (ChOD) and horseradish peroxidase (HRP) activating the reaction steps served as input signals (Input signal A, Input signal B and Input signal C), which can be presented as the network composed of three concatenated AND gates. The output signal of the concatenated gates system was measured as the absorbance change (λ=652nm) of the bio-catalytically oxidized3,3’,5,5’-Tetramethylbenzidine (TMB). When the output siganl of logic gates was1, we can use the organic pesticides dimethoate inhibition of acetylcholine to analysis of the pesticides. It exhibits a wide linear range from1～20μg mL-... |
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