Basic Research On The Preparation And Application Of Polypyrrole And Its Derivative-based Nanocomposites

The rhythm of people's life is accelerated with advanced in science and technology and the rapid development of society as well as the increasing pressure in work and life.Frequent high-intense work can lead to chronic illnesses such as metabolic disorders,schizophrenia,depression,diabetes,high blood pressure and even cancer.The content level of ascorbic acid(AA),dopamine(DA)and uric acid(UA)in the human body directly affects people's health,for instance,lack of AA can lead to scurvy,lack of DA can cause some neurologicalb disorders such as schizophrenia,depression and Parkinson's disease etc,a high level of UA in the blood can result in hyperuricemia,and UA metabolism disorder is the cause of gout.Therefore,it is of great significance to rapidly and accurately determine the contents of the three chemicals(AA,DA and UA).On the other hand,chemotherapy and photothermal therapy are usually employed in the treatment of cancer,however,the common anticancer drugs used in chemotherapy generally with shortcomings including poor solubility in aqueous,toxic and side effects.So,it is necessary to develop a novel drug carrier with high drug loading and the ability to combine photothermal and chemotherapy.The ultilization of polypyrrole and its derivatives in the fields of electrochemical sensors and biomedicine has attracted much attention because of its good biocompatibility,photothermal effect and electrical conductivity.Based on above inspiration,this study conducted the following two aspects of work:1)Novel multi-walled carbon nanotubes coated with poly[N-(ferrocenyl formacyl)pyrrole](MWCNTs@PFFP)nanocomposites were prepared through the in situ oxidation polymerization reaction of N-(ferrocenyl formacyl)pyrrole in the presence of MWCNTs.The MWCNTs@PFFP nanocomposites were characterized by FT-IR,Raman,TGA,XRD,XPS,SEM and TEM techniques.The MWCNTs@PFFP nanocomposites were fabricated into novel electrochemical sensors for simultaneous determination of ascorbic acid(AA),dopamine(DA)and uric acid(UA).The electrochemical behavior of the MWCNTs@PFFP/GCE sensors was examined,and the parameters that influence electrochemical signals were optimized.The experimental results showed that the fabricated modified electrode sensors exhibited good sensitivity,selectivity,repeatability and a long lifetime,remaining the initial current of at least 92.5%after 15 days storage in air.The sensors possessed a linear response concentration range over 200-400 ?M for AA,2-16 ?M for both DA and UA,and a limit of detection as low as 40.0,1.1 and 7.3 ×10-1?M for AA,DA and UA,respectively.They are expected to be used as a potential tool for simultaneous detection of DA,AA and UA in human body.2)A novel hollow polypyrrole coated by mesoporous silica nanoparticles graft P(2-(4-formylbenzoyloxy)ethyl methacrylate)-co-P(2-(dimethylamino)ethyl methacrylate)-b-P(triethylene glycol methyl ether methacrylate)multifunctional hybrid capping material(HPPy@MSN-SS-NH-g-P(FBEMA-co-DMAEMA)-b-PTGMEMA)is designed and prepared via disulfide bonds.This material as a gatekeeper integrated the multiple functions such as pore capping,high drug-loading,and pH and potothermal reductant multistimuli response abilities.It could entrap anticancer drug doxorubicin(DOX)by pore channels of HPPy@MSN,the micelle core of hydrophobic copolymers and Schiff base linkages,offering a loading capacity and load efficiency of up to about 41.54 and 83.08%,respectively.In the meanwhile,the DOX-loaded multifunctional materials could achieve intracellular chemo-photothermal combination therapy against cancer cells by controlling the mesopore on-off based on gatekeepers,different tumour environments including pH and reductant stimuli,and good near-infrared(NIR)photothermal conversion capacity of HPPy.The drug-loaded carriers exhibited optimal drug release dynamics in cancer tissues compared with in normal cells upon triggered by pH and GSH under the NIR irradiation.The newly-developed material possessed good photothermal stability and high dispersity stability in aqueous solution.Therefore,it can be used for comprehensive therapy of cancer as a promising candidate of drug delivered carriers.