Preparation Of Transition Metal Doped Nanocomposites And Their Application In Analytical Chemistry

Hydrogen peroxide（H₂O₂）,glucose（Glucose）,dopamine（DA）,and uric acid（UA）are some small biological molecules in the human body that play a vital role in human health.Abnormal levels of these small biomolecules in the human body can cause various diseases.Therefore,finding analytical methods that can detect these small biomolecules quickly and sensitively is particularly important.Electrochemical detection methods and colorimetric detection have attracted wide attention due to their simplicity,low cost and high sensitivity.In this paper,composite materials loaded with different transition metals were prepared,and these materials were used as electrode modification materials or enzyme mimetics to construct biosensors to detect corresponding substances to be tested.The specific research content includes the following three parts:（1）Ni@Pt/r GO nanocomposites was prepared by a two-step reduction method.Thus obtained Ni@Pt/r GO nanocomposite was characterized by transmission electron microscopy（TEM）,scanning electron microscopy（SEM）,X-ray diffraction（XRD）,energy dispersive spectroscopy（EDS）and X-ray photoelectron spectroscopy（XPS）.Moreover,the as-prepared Ni@Pt/r GO composite was modified on the surface of a bare glassy carbon electrode（GCE）as a electrochemical sensor for glucose detection.The sensor showed good detection performance with a detection limit of 8μM and a linear range of up to 10.008 m M.（2）Pt Ni bimetallic nanoparticles were loaded on Mo S₂nanosheets by co-reduction method to obtain Pt Ni@Mo S₂nanocomposite which was then characterized by TEM,SEM,XRD,EDS and XPS.Then,the the obtained material was used to fabricate an electrochemical sensor（Pt Ni@Mo S₂/GCE）for the simultaneous detection of DA and UA.A good detection performance with low detection limits（down to 0.1μM for both anlytes）,wide linear ranges（DA:0.5-150μM,UA:0.5-600μM）and high selectivity was obtained.（3）PB-Au@Mo S₂NFs nanocomposites was synthesized by a simple green method and characterized by XRD,SEM,and EDS.The peroxidase-like activity of Mo S₂nanoflowers is significantly enhanced by the loading of PB and Au nanoparticles.Based on this,We used,UV and colorimetric detection of analytes H₂O₂and glucose were successfully obtained using 3,3’,5,5’-tetramethylbenzidine（TMB）as the substrate.The detection linear ranges for H₂O₂and glucose were 0-15μM and 0-120μM,respectively.And the detection limits were 0.25μM and 3μM（S/N=3）,respectively.This test platform has been used for the detection of glucose in plasma and fruits which showed good analytical results.