Study On The Fabrication Of Nanomaterial-based Sensors And Application In Detection Of Glutathione

Glutathione is a functional molecule which is indispensable to a large number of human vital activities.It plays an essential role in the control of biological activity of proteins and the metabolism of human body.Furthermore,the concentration level of GSH in the serum is a physiological indicator of various diseases involving Parkinson's and diabetes.Therefore,the efficient,rapid and accurate measurement of GSH in serum samples is of important clinical significance for the early screening of certain serious diseases.Due to the advantages of low cost,high sensitivity,fast response,good selectivity,simple instrumentation and easy miniaturization,the electrochemical detection method was employed for the GSH detection.The multi-walled carbon nanotubes-reduced graphene oxide nanoribbon core-shell structure nanomaterials?MWCNT@rGONR?,porous NiO nanosheets?NiO NS?nanomaterials were utilized to modify electrodes to improve the detection efficiency on GSH.At the same time,in order to explore the application of GSH detection by fluorescence,5,10,15,20-tetramethylacryloxyphenyl porphyrin?TMaBPP?-Hg²⁺system was constructed to detect the GSH and its thiol analogs.The main research work of this dissertation is as follows:?1?MWCNT@rGONR core-shell nanocomposite was successfully prepared by solution stripping and the nanomaterial was modified on glassy carbon electrode?GCE?for electrochemical detection of GSH.The morphology and structure of the prepared materials were systematically characterized using SEM,TEM and FTIR.The electrochemical properties of the sensor for GSH detection were thoroughly investigated by cyclic voltammetry?CV?,electrochemical impedance spectroscopy?EIS?,and amperometry?i-t?.Under the optimal conditions,the GSH sensor showed good electrocatalytic performance,excellent electrical conductivity and high electron transfer efficiency,and wide linear ranges of 0.05²66.3?M and 266.3⁷66.3?M was obtained.And a low detection limit of 39 nM?S/N=3?was acquired.In addition,the developed sensor also displayed good selectivity,reproducibility and stability.Finally,the practicability and accuracy of the designed sensors were verified by standard addition method to determine the recovery rate of GSH in a closed normal human serum sample.The MWCNT@rGONR core-shell nanomaterials showed a vast potential for the application in electrochemical sensing platform.?2?NiO NS were prepared by hydrothermal reaction and calcination at high temperature,and an electrochemical sensor based on the porous nanomaterial was successfully constructed for the electrochemical detection of GSH.The surface morphology and crystal structure of NiO NS were characterized by SEM,TEM,EDX,XRD and XPS.The electrochemical behavior of the sensor was studied using electrochemical analysis methods such as CV,EIS and i-t.The porous lamellar structure of NiO NS increases its surface active sites,making the proposed sensor possess excellent electrocatalytic performance with faster response,a wide linear range?0.005³166.655?M?,and low detection limit?2.34 nM,S/N=3?,as well as good selectivity,reproducibility and ideal stability.Finally,the standard GSH was spiked in closed normal human serum samples to verify the practicability and accuracy of the sensor.All of these results demonstrate that NiO NS exhibited unparalleled research value in the electrochemical detection of GSH,which provide a reference for the further application of this nanomaterial.?3?A highly sensitive TMaBPP porphyrin derivative molecule was designed and synthesized.The TMaBPP-Hg²⁺system was established and successfully used for fluorescence detection of GSH and its thiol analogs.The molecular structure of TMaBPP were analyzed by ¹H-NMR,FTIR,FS,UV-vis,etc.,and the effect of TMaBPP-Hg²⁺system on the detection of GSH and its thiol analogues was examined by fluorescence spectroscopy.The results showed that the TMaBPP-Hg²⁺fluorescence sensor has a fast detection speed?transient response<1s?and achieved wide linear ranges?GSH:0.005-0.1?M and 2.5¹000?M,Cys:0.01².5?M and 2.5⁷50?M,Hcy:0.1⁵?M and 5¹000?M?,lower detection limits?0.5 pM,11.57 pM,and 50.64pM?S/N=3?detection limit for GSH,Cys,and Hcy,respectively?,and good selectivity,reproducibility and ideal stability.Finally,the standard GSH and its thiol analogues were spiked in the closed normal human serum samples to verify the practicality and accuracy of the developed sensor system.