▎ 摘　　要

NOVELTY - Nickel particle modified carbon matrix prepared by catalyzing a nitrogen-doped carbon nano tube/graphene composite sheet structure in situ by apical effect, is claimed. USE - The nickel particle modified carbon matrix is useful in mass spectrometry analysis of metabolic small molecules of gastric cancer (claimed) and synthesizing nickel particle modified nitrogen-doped carbon nanotube/graphene composite. ADVANTAGE - The nickel particle modified carbon matrix: has a large specific surface area of 100-300 m2/g, good ultraviolet absorption capacity at 355nm and absorbance value of 0.350.56, strong electron donor performance; can be used as a fresh type of mass spectrometry carbon matrix to enhance the analytical ionization effect of low molecular weight substances, and apply to the analysis of small molecular metabolites with m/z less than 700; can also be used in the application of gastric cancer saliva metabolite detection and screening methods; prepares nickel particle modified nitrogen-doped carbon nanotube/graphene composite with low cost and simple preparation method; can meet mass production and realize industrialization; and provides detection method with high throughput, rapidity, high sensitivity, etc., and potential to be applied to clinical early gastric cancer patient screening. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for: (1) preparing nickel particle modified carbon matrix, comprising (i) dispersing nickel acetate tetrahydrate into the solution of polyvinylpyrrolidone, dripping slowly the above mixed solution into the graphene oxide solution under stirring conditions, mixing uniformly to form a gel, maintaining it for 12 hours, and freeze-drying, (ii) reducing the product under heat at high temperature under hydrogen/argon atmosphere to obtain graphene modified with nickel particles, (iii) carbonizing the product under the protection of argon gas at a high temperature by a vapor deposition method to obtain a nitrogen-doped carbon nano tube/graphene composite modified by nickel particles and (iv) dispersing the nitrogen-doped carbon nano tube/graphene composite modified by nickel particles in a 1:1 mixed solution of ethanol and water volume ratio, and using as a substrate; and (2) application of a nickel particle modified carbon matrix in the mass spectrometry analysis of metabolic small molecules of gastric cancer., comprising (a) carrying out matrix-assisted laser desorption ionization time-of-flight mass spectrometer and positive ion mode mass spectrometry detection, (b) drop-coating the nickel particle-modified carbon matrix on the matrix-assisted laser desorption ionization target plate, and drying it at room temperature to obtain a thin-layer matrix, (c) spotting the analysis sample on the surface of the thin-layer matrix, forming the sample and the thin-layer matrix into secondary recrystallization after drying and carrying out the ionization mass spectrometry detection and (d) analyzing the results of mass spectrometry and drawing conclusions.