Medical Small Molecule Electroanalysis Technology Based On Copper Nanocomposite Materials

Copper?Cu?metal nanomaterials have been widely used in the fields of photocatalysis,contaminant removal,and sensing analysis,due to some outstanding merits like good electrical conductivity,adsorption,and catalytic activity.In this thesis,some functional nanocomposites of Cu and melamine?MA?or metal organic frameworks have been prepared and modified onto the electrodes for the highly sensitive analysis of glutathione?GSH?,histidine?His?,and histamine?HTA?.These contents mainly include:?1?An electrochemical sensor was developed with melamine-copper?MA-Cu?nanocomposites for the electroanalysis of GSH separately in Hela cells and yeast cells?Chapter2?.MA-Cu nanocomposites were synthesized by the controlled supramolecular self-assembly method showing different morphological structures depending on the ratio of MA to Cu.It was found that the electrodes modified with rod-like MA-Cu nanocomposites could obtain the stable solid-state CuCl electrochemical output at a low potential.Moreover,once GSH as introduced,the yielded CuCl signals would decrease resulting from the specific Cu-GSH interaction that would trigger the displacement of CuCl into non-electroactive Cu-GSH complex.The developed electroanalysis strategy may avoid the interference from electroactive substances coexisting in complicated backgrounds like cells.Importantly,it was demonstrated for the evaluation of GSH separately in Hela and yeast cells with high sensitivity and selectivity.?2?A wettable well-based electrochemical sensor has been desiged using hollow graphene quantum dot?GQD?-scaffolded MA-Cu nanocomposites?GQD@MA-Cu?for the electroanalysis of His in urine?Chapter 3?.Gold electrode was first spotted with polyacrylic acid to form hydrophilic testing dot and then patterned with hydrophobic hexadecyltrimethoxysilane,followed by etching the testing dot to yield the well.The resulted GQD@MA-Cu well-modified gold electrode was employed further for the electroanalysis of His through the solid-state CuCl electrochemistry,of which the specific Cu-His interactions would trigger the rational decrease in the CuCl oxidation peak currents.Moreover,benefitting from the wettability feature,the well on the gold electrode could facilitate the condensing enrichment of His analytes from the sample droplet achieving the improved analysis sensitivity.A sensitive and specific electroanalysis strategy was subsequently demonstrated for the detection of His in urine.?3?An electrochemical sensor has been constructed using copper metal organic frameworks?Cu MOFs?for the electroanalysis of His in blood?Chapter 4?.Cu MOFs with octahedral structure were prepared simply by the one-step solvothermal reaction route,which were further modified onto the electrodes.It can facilitate the His detection through the stable“turn-on”signal output of solid-state CuCl electrochemistry at a potential approaching to zero,which may help to avoid the possible electroactive interferents co-existing in the complicated media such as blood.The developed electroanalysis strategy was achieved for the evaluation of His in blood.?4?An electroanalysis technique has been developed for sensing HTA and His separately in red wine and urine using reduced copper metal-organic frameworks?Cu MOFs??Chapter 5?.Cu MOFs were first reduced NaBH₄ to produce Cu nanocomposites?NCs?and then were modified onto the electrodes.It was discovered that the Cu NCs-modified electrodes could display more stable electrochemical oxidation peaks of solid-state CuCl at a low potential.More importantly,once HTA or His was added,the peaking currents of the as-prepared electrodes would increase because of the strong interaction between Cu and the imidazole groups of HTA and His.This electroanalysis method can allow for the highly specific electrochemical detection of HTA in red wine and His in urine in the concentration range of 0.010-100?M.