Construction And Application Of Organic Polymer Composites Electrochemical Sensor

Peroxynitrite anion（ONOO^-）is a kind of RNS,formed through the reaction of superoxide anion radical(O₂^·-)and nitric oxide radical（NO^·）.The abnormal level of ONOO^-in the biological system can cause cell damage and produce oxidative stress.It is reported that many diseases are contacted with overproduction of ONOO^-in biological systems,such as diabetes,bleeding disorders and atherosclerosis.Therefore,the detection of ONOO^-concentration is necessary in biological systems.In this work,two types of ONOO^–electrochemical sensors were prepared using simple methods,which can be applied to detect ONOO^–released from cells.The main contents are as follows:（1）Organic polymer nanotubes（OPNTs）were prepared through a simple Friedel Crafts reaction.Their morphology and structure were characterized by scanning electron microscopy（SEM）and transmission electron microscopy（TEM）.And it was found that OPNTs have the hollow tubular structure with neat arrangement.Then,a new kind of peroxynitrite anion（ONOO^-）electrochemical sensor was constructed by modified of OPNTs on the glassy carbon electrode.Such OPNTs/GCE showed a wide linear range（23.4 n M-0.174 m M）and a detection limit as low as 7.43 n M（S/N=3）,with a sensitivity of 1.41μA·μM^-1cm^-2.In addition,OPNTs/GCE exhibited excellent performance in terms of selectivity,reproducibility and stability,and can monitor ONOO^-released from He La cells.At the same time,we also studied the ability of tea polyphenols（TP）by the electrochemical method,which used as an antioxidant to scavenging ONOO^-in biological systems.This work provides an effective strategy for protecting cells from oxidative stress.（2）On the basis of above chapter,carbon quantum dots（CDs）were prepared by aqueous phase synthesis method first,which have excellent conductivity.Then,a novel ONOO^-electrochemical sensor was constructed by combined with OPNTs.CDs/OPNTs/GCE showed excellent analytical performance for ONOO^-detection,with a wide linear range of 1.74 n M-357μM,and a low detection limit of 0.58 n M（S/N=3）.The electrochemical sensor had good selectivity,stability and reproducibility.In addition,this work can be applied to detect ONOO^-in human serum samples by using the standard addition method.And the recovery rate of standard addition is in the range of 92.9%-101.6%,which has potential practical application value.Our work provides new ideas for the design and direct detection of ONOO^-sensors.