190 results about "Pulse voltammetry" patented technology

The invention relates to a method for preparing an electropolymerized sulfosalicylic acid modified glassy carbon electrode, and use of the glassy carbon electrode as a tryptophan electrochemical sensor in high-sensitivity measurement of tryptophan in compound amino acid injection, and belongs to the technical field of electrochemical analysis and detection. The invention mainly aims to prepare the electropolymerized sulfosalicylic acid modified glassy carbon electrode to perform sensitive quantitative analysis and measurement on the tryptophan by a differential pulse voltammetry. Experimental results show that: the modified electrode has an obvious sensitization effect on the tryptophan in a phosphate buffer solution at the concentration of 0.1mol / L and the pH of 3.5, and under the optimal conditions, the differential pulse voltammetry is adopted for measurement, and the tryptophan at the concentration in a range of 5.0*10<-8>-4.0*10<-4> and peak current of the tryptophan have a good linear relation, and the detection limit is 4.0*10<-8>. When the method is used for measuring the tryptophan content in a medicine, results are satisfactory.

The invention discloses an electrochemical sensor for adapters and a method for detecting chlorpyrifos. The electrochemical sensor adopts a three-electrode system and comprises a first detection layer, a second detection layer and a fixed layer. A preparation method comprises the following steps of: preparing copper oxide nanoflower solution, preparing single-wall carbon nanotube solution, treating base electrodes, activating carboxyl groups, and fixing probes and the adapters; and then manufacturing a standard curve by utilizing a differential pulse voltammetry, and finally calculating out the concentration of the chlorpyrifos in samples according to the standard curve of the chlorpyrifos. The electrochemical sensor and the method disclosed by the invention have the advantages that the detection for the chlorpyrifos is specific, the sensitivity and the selectivity are high, the renewability is achieved, the materials are wide in source, the cost is low, and the preparation method is simple, so that the application prospect is good.

The invention discloses an electrochemical sensor for detecting nitrite, a preparation method and application, and belongs to the field of electrochemical analysis. The preparation method comprises the following steps of: etching aluminum carbide to obtain titanium carbide with of accordion-like structure, calcining the titanium carbide serving as a titanium source to obtain titanium dioxide-titanium carbide, dispersing the compound into a solution containing hexadecyl trimethyl ammonium bromide and chitosan, and performing ultrasonic treatment to obtain a composite solution. According to theelectrochemical sensor for detecting nitrite, the preparation method and the application, a three-electrode system is adopted, a glassy carbon electrode modified by a titanium dioxide titanium carbide / hexadecyl trimethyl ammonium bromide / chitosan compound is used as a working electrode, and the nitrite is determined by differential pulse voltammetry. The electrochemical sensor disclosed by the invention has the advantages of high sensitivity, good selectivity, low detection limit, quick response and the like in nitrite detection, and has a wide application prospect in the aspects of environment and food detection.

The invention discloses a graphite phase nitrogen carbide-chitosan modified electrode, a preparation method thereof, and a method using the same as a work electrode to detect protocatechuic acid. The preparation method comprises the following steps: directly heating melamine to synthesize g-C3N4, preparing g-C3N4 nano sheets through liquid phase peeling, and then utilizing a self-assembling method to fix g-C3N4 and chitosan onto the surface of a glass-carbon electrode in sequence so as to construct a graphite phase nitrogen carbide-chitosan modified electrode. The detection method of protocatechuic acid comprises the following steps: utilizing the graphite phase nitrogen carbide-chitosan modified electrode as the work electrode, through a differential pulse voltammetry, and drawing a curve representing linear relationship between the corresponding current and the protocatechuic acid concentration so as to analyze the protocatechuic acid in the environment quantitatively and qualitatively. The provided electrode has good chemical responding to protocatechuic acid, has a strong anti-interference performance, and can be used to detect an actual sample. The detection method has the advantages of simple operation, short time, little using amount, and low cost, and a novel thinking is provided for the detection of phenolic acids.

The invention relates to a polymethyl blue / acetylene black composite modified glassy carbon electrode prepared by an electrodeposition method and a dispensing method. The electrochemical behavior of acetaminophen (PCT) on the modified electrode is studied by a cyclic voltammetry (CV). The experimental result shows that the modified electrode has a good electrocatalytic performance for the redox of PCT. Compared with a bare electrode and a polymethyl blue-acetylene black modified electrode, the oxidation peak current of PCT on the polymethyl blue / acetylene black modified glassy carbon electrode is obviously improved. Through the determination of a differential pulse voltammetry (DPV), the PCT has a good linear relationship with the oxidation peak current in the concentration range of 2.0 multiplied by 10<-6> to 0.4 multiplied by 10<-3>mol / L, and the correlation coefficient is 0.992, and the detection limit of PCT is 1.0 multiplied by 10<-6>mol / L when the signal to noise ratio is 3.

The invention discloses a sensor used for detecting circulating tumor cells via differential pulse voltammetry. A preparation method of the sensor comprises following steps: vanadium pentoxide nanowires and gold-silver core-shell nanoparticles are prepared via a conventional method; the vanadium pentoxide nanowires and gold-silver core-shell nanoparticles are combined so as to modify aptamers; the surface of an electrode is modified with gold nanoparticles, and then the modified electrode is connected with the vanadium pentoxide nanowire gold-silver core-shell nanoparticle modified thiolation aptamers; the obtained electrochemical sensor is used for detecting circulating tumor cells via combination with an electrochemical workstation; and the electrochemical workstation is used for detecting. The sensor is high in specificity and sensitivity; operation is simple; and detection limit is low.

The invention discloses preparation of a graphene-based carboxymethylcellulose nanocrystalline composite material. The preparation of the graphene-based carboxymethylcellulose nanocrystalline composite material comprises mixing graphene oxide dispersion liquid with sodium carboxymethylcellulose aqueous solution, and meanwhile adding in ethanediamine and a cross-linking agent of N-N-hydroxysuccinimide for continuous reaction at 48-55 DEG C for 50-53 h; then, adding in hydrazine hydrate to reduce superfluous oxygen-containing functional groups and carbon-oxygen double bonds on graphene oxide, and then performing suction filtration, washing and drying to obtain the graphene-based carboxymethylcellulose nanocrystalline composite material. Through a dripping method, the graphene-based carboxymethylcellulose nanocrystalline composite material is modified on a glassy carbon electrode to form an electrochemical chiral sensing interface, and the electrochemical chiral sensing interface is arranged inside L-tryptophan or D-tryptophan solution separately and scanned through differential pulse voltammetry. Due to the fact that the steric hindrances as well as the peak currents when L-tryptophan and D-tryptophan interact with the modified electrodes are different, the graphene-based carboxymethylcellulose nanocrystalline composite material can help rapidly and sensitively achieve recognition of tryptophan isomers.