47results about How to "Detection line low" patented technology

The invention discloses a metal ion-labeled immunoreaction single-pulse detection method, which realizes single-pulse signal detection by using inductively coupled plasma or microwave plasma mass spectrometry analysis technology, and uses metal nanoparticles to mark the immune reaction, and further utilizes inductively coupled Plasma or microwave plasma mass spectrometry technology detects the pulse signal of metal ions that mark the immune reaction, so as to achieve the purpose of indirect detection of the analyte.

The invention discloses a preparation method and a use of a functional graphene-loaded palladium nanoparticle composite material. The preparation method comprises the following steps of carrying out ultrasonic dispersion of graphene in water to obtain a graphene suspension liquid, adding a pyrenetetrasulfonic acid sodium salt aqueous solution into the graphene suspension liquid, carrying out heating stirring for 8-15h, carrying out centrifugal filtration to obtain functional graphene, dispersing the functional graphene in water to obtain a functional graphene suspension liquid, adding a palladium chloride solution into the functional graphene suspension liquid, adding a sodium borohydride solution into the mixed solution, carrying out heating stirring for 8-15h, and carrying out centrifugal filtration to obtain the functional graphene-loaded palladium nanoparticle composite material. Through functionalization of graphene by the pyrenetetrasulfonic acid sodium salt, dispersibility and stability of graphene and palladium nanoparticles are improved. A glassy carbon electrode modified by the functional graphene-loaded palladium nanoparticle composite material has a good nitroaromatic compound catalysis performance, a low nitroaromatic compound detection limit, a wide nitroaromatic compound detection linear range, high nitrobenzene detection sensitivity, a nitrobenzene detection linear range of 170-8ppb, and a nitrobenzene detection limit of 0.62ppb.

The invention relates to preparation and application of a competitive immunosensor, in particular to a competitive immunosensor which takes a composite material of UiO-66 and gold nanoparticles (UiO-66 / Au) as a sensing platform and NH2-MIL-125 as a marker, and belongs to the technical field of novel functional materials and biosensing. The UiO-66 / Au has excellent electrical conductivity and largespecific surface area, so that the electron transfer process can be effectively promoted and the roles of amplifying the current signal and increasing the sensitivity of the sensor are played; and theNH2-MIL-125 synthesized by utilizing an one-pot method has large steric hindrance to ensure that the electron transfer can be hindered and the current signal is reduced, so that the changing value ofthe current signal is increased, the content of a target can be detected by utilizing the change of the electrochemical signal by the sensor; and therefore, the stability and the sensitivity of the immunosensor are significantly increased, the detection range is expanded and the detection limit is reduced.

The invention provides a method for detecting trivalent chromic ions by using a rhodamine fluorescent probe, and is characterized in that the method includes the steps: preparing trivalent chromic ion solutions with different concentrations, allowing to stand, under a condition of the excitation wavelength of 560 nm, detecting the fluorescence intensity at the emission wavelength of 582 nm, and with the concentration of chromium ions as an abscissa and the fluorescence intensity as an ordinate, mapping to obtain a linear relationship curve; adding a rhodamine fluorescent probe solution to an NaOH / NaH2PO4 buffer solution to obtain a buffer system containing the fluorescent probe, adding a to-be-tested trivalent chromic ion solution, allowing to stand, under a condition of the excitation wavelength of 560 nm, detecting the fluorescence intensity at the emission wavelength of 582 nm, and according to the linear relationship curve obtained in the step 4, calculating the concentration of the chromium ions. The fluorescent probe can selectively identify the trivalent chromic ions, is free from the interference of other common ions, and is high in fluorescence intensity.

The invention discloses an ion-selective electrode flow injection analyser. Ports of a three-way valve are connected with an ion selective electrode (ISE), a No.1 channel of a six-way valve and a peristaltic pump; the other end of the peristaltic pump A is connected with a total ionic strength adjustment buffer (TISAB) bottle; two ends of a peristaltic pump B are connected with a carrier liquid bottle and a No.6 channel; two ends of a peristaltic pump C are connected with a waste liquor bottle and a No.4 channel; a sample liquid bottle is connected with a No.3 channel; two ends of a separation column are connected with a No.2 channel and a No.5 channel; the bottom end of the ISE is provided with an ISE electrode membrane, a reflux tube is arranged below the ISE electrode membrane, and a gap between the reflux tube and the ISE electrode membrane is 0.5mm; a reference electrode and the ISE electrode are connected through a gravity separator consisting of an A-B channel and a C-D channel; inclination angles of the A-B channel and the C-D channel are 35 degrees and 45 degrees; and channels on two sides of the reflux tube are connected with the ends B and D of the gravity separator. The ion-selective electrode flow injection analyser has the advantages that: experimental reagents are saved, a detection line can be reduced, and a phenomenon that the detection limit is improved due to the dissolution of a salt type ISE membrane is inhibited.

The invention relates to a preparation method and application of a fluorescent probe that can be used for ammonia gas detection and a test paper thereof, and belongs to the technical field of analytical chemistry. The fluorescent probe of the present invention takes the benzo[a]phenoxazine nucleus as the parent nucleus, and its chemical structure is shown in formula (I). The fluorescent probe with NH 3 When acting, the intramolecular charge transfer effect is significantly enhanced, showing red fluorescence, realizing NH 3 detection. In addition, the fluorescent probe of the present invention can also be prepared into a test paper to realize the rapid detection of ammonia gas, and also has very important practical value for the determination of ammonia gas content in the ammonia breath experiment and the diagnosis of Helicobacter pylori.