Preparation Of Functionalized Nanozymes And Research On Their Efficient Biosensing Application

The birth of nanozymes has promoted the development of many fields,such as biosensing.Due to its excellent catalytic activity and good physical and chemical properties,it can be broadly applied on analysis and sensing.The construction of economical and multi-site nanomaterials has become the focus of nanomaterials research.Currently,nanozymes have been used in colorimetric probes,but their selectivity for analytical sensing is limited due to their limited variety.The selectivity and sensitivity of the sensor can be improved if the nanozymes are designed intelligently and rationally according to the requirements,so as to achieve efficient biosensing detection.The selectivity and sensitivity of the sensor can be improved if the nanozyme is designed intelligently and rationally according to the requirements,so as to achieve efficient biosensing detection.Based on this,this work has made research on the sensing ability of xanthine（X）functionalized molybdenum oxide nanozyme(X-Mo O_3-x)for xanthine oxidase（XO）analysis and polymyxin B（Pm B）modified Fe-C nanodots（Fe-C NDs@Pm B）for lipopolysaccharide（LPS）quantification.The main research contents are as follows:1.As an oxidoreductase required by human body,xanthine oxidase is closely related to human health.Excessive concentration of xanthine oxidase in serum will lead to diseases such as gout and liver injury.Therefore,it is necessary to develop a transition metal nanozyme with good dispersity and specific recognition of xanthine oxidase and apply it to the analysis and sensing of xanthine oxidase.The prepared molybdenum oxide nanozyme(X-Mo O_3-x)were evenly dispersed and had stable peroxidase（POD）activity.Because xanthine can specifically recognize xanthine oxidase and decompose to produce hydrogen peroxide（H₂O₂）.Therefore,the xanthine oxidase activity detection based on X-Mo O_3-xrequire no extra addition H₂O₂.This ingenious design realizes the specific detection of xanthine oxidase,with a linear range of 0.1-0.5 U/m L and a limit of detection 0.06 U/m L.The recoveries were 98%-115%.In addition,the successful detection of human serum samples verifies the feasibility of the sensor platform in practical scenarios.2.Although colorimetric sensing method can achieve highly selective detection,it is also worth considering to improve the sensitivity of sensing.Therefore,it is extremely urgent to design a high sensitivity two-channel analytical sensing method.When gram-negative bacteria die,the bacterial cell wall secretes the toxic factor LPS,which when exposed to human blood will lead to various inflammatory reactions in the human body,and even lead to multiple organ failure.Therefore,in this study,Fe-C nanodots（Fe-C NDs）were prepared,and the nanodots were modified with polymyxins B（Pm B）,which can specifically recognize lipopolysaccharides.The synthesized Fe-C NDs@Pm B not only had excellent peroxidase-like activity,but also had good fluorescence properties.Moreover,it has good selectivity to LPS.Fe-C NDs@Pm B has been successfully applied on colorimetric sensing（linear range 15-100μg/m L）and fluorescence sensing（linear range 20-150 ng/m L）with a limit of detection 11.87 ng/m L.The recoveries were 97.7%-112.5%.Finally,the practical test results of the actual samples confirmed the practicability of the two-channel sensing platform,which provided a new idea for the development of analytical methods for the detection of LPS.