10 results about "Core shell nanostructure" patented technology

This invention discloses a method for fabricating and applying a formaldehyde SERS sensor based on an Au@ZIF-8 core-shell nanostructure, belonging to the field of gas detection technology. Formaldehyde has an extremely small intrinsic Raman cross section, and ordinary SERS substrates lack the ability to capture it, resulting in weak detection signals at low concentrations. This sensor uses Au@ZIF-8 core-shell nanoparticles to assemble a two-layer thin film as the SERS substrate. The Au nanoparticles (AuNPs) serve as the electromagnetic enhancement core, while the ZIF-8 shell layer enriches and sieves formaldehyde molecules. A layer-to-layer deposition method is used to construct the double-layer thin film structure to obtain optimal SERS performance. This invention solves the problems of low sensitivity, poor specificity, insufficient stability, and difficulty in rapid on-site detection in existing formaldehyde detection technologies. The detection limit is as low as 0.16 ppt, and within a wide range from 0.01 ppb to 100 ppm, the characteristic peak intensity exhibits an excellent linear relationship with the logarithm of formaldehyde concentration (R² ≥ 0.995). It can specifically identify formaldehyde and exclude interference from other VOCs, making it suitable for rapid quantitative detection of formaldehyde in practical scenarios such as indoor environments and cigarette smoke.

This invention discloses a near-single-molecule-limit quantum biosensor and detection method. By integrating a notched coplanar microwave waveguide, a plasma-enhanced gold nanoisland array, and a semi-arc-shaped framework chaotic hybrid microfluidic structure on a single chip, it achieves a high degree of integration of optical, microwave, and fluid reaction systems, improving mixing efficiency and reaction kinetics under microfluidic conditions, reducing diffusion limitations, and increasing capture efficiency, thereby shortening detection time. It enables rapid quantitative detection of atmolar-level miRNAs and has multiplex detection capabilities. The plasma nanogap formed by the gold nanoislands and gold-silver core-shell nanostructures can enhance the contrast of NV center fluorescence readout and ODMR, improve the signal-to-noise ratio, and significantly improve the detection limit and quantitative stability of ultra-low abundance miRNAs.

The application belongs to the technical field of Raman substrates, and particularly relates to a preparation method and application of a patterned silver-coated gold Au@Ag nanostructure substrate. The patterned silver-coated gold Au@Ag nanostructure substrate in-situ synthesizes an Ag shell layer by taking patterned Au nanostructures with uniform particle sizes and close packing as a template, the Ag uniformly wraps each Au nanoparticle, and a high-quality patterned silver-coated gold Au@Ag core-shell nanostructure is obtained, without introducing any additional stabilizer and without a complex experimental step flow, and the stable and universal preparation of the SERS substrate with high sensitivity and high enhancement uniformity provides a reference. Due to the synergistic effect of Au and Ag, the SERS effect of the substrate is enhanced, the Raman enhancement effect of the nanostructure is stronger than that of the patterned Au nanostructure, which is more conducive to the detection and analysis of molecules, and the problem of easy oxidation of the Ag shell is avoided, and the nanostructure has good signal enhancement uniformity.

The application discloses a kind of core-shell nanostructure magnesium hydride-magnesium borohydride hydrolysis hydrogen production materials and preparation method thereof.A kind of core-shell nanostructure magnesium hydride-magnesium borohydride hydrolysis hydrogen production material preparation method, comprising the following steps: magnesium hydride is loaded into ball mill jar vacuum, then borane gas is filled in ball mill jar, ball milling treatment is carried out, and the core-shell nanostructure magnesium hydride-magnesium borohydride hydrolysis hydrogen production material is obtained.The application uses solvent-free gas-solid reaction, ball milling method, simple, low cost;This composite method not only avoids the direct use of expensive magnesium borohydride, but also overcomes the shortcomings of other composite systems, and even improves the theoretical hydrogen release capacity;The in-situ formed magnesium borohydride nanoshell plays a key role in improving the hydrolysis kinetics of magnesium hydride by releasing heat and forming a local magnesium ion and metaborate ion solution environment.

The invention discloses a core-shell parameter optimization SERS (Surface Enhanced Raman Scattering) signal regulation and control method, and particularly relates to the technical field of nano materials, comprising the following steps: S1, defining optical parameters of a target structure; s2, multi-source signals are synchronously acquired in real time; s3, generating fed-batch decision logic; s4, performing regulation and control execution and response evaluation; and S5, terminating judgment when the performance reaches the standard. According to the core-shell parameter optimization SERS signal regulation and control method disclosed by the invention, preparation of a core-shell nano structure is converted from open-loop empirical operation to closed-loop quantitative regulation and control. A geometric parameter combination with the strongest theoretical enhancement effect is screened out in advance through electromagnetic simulation, and the optical formant position of the geometric parameter combination is defined as a target value of the preparation process, so that the synthesis process has clear and quantitative optical performance guidance; raman characteristic peak intensity reflecting SERS signal intensity, plasma resonance peak position reflecting structure formation and particle size polydispersity index reflecting particle aggregation state are synchronously acquired in situ.

This invention proposes a simple and easy-to-operate method for preparing core-shell quantum dots that suppress Auger recombination, and develops Mn-doped CsPbCl3@Cs4PbCl6 core-shell nanocrystals. The Auger suppression performance was studied using wavefunction engineering. The method includes the following steps: ① Synthesizing CsPbCl3 nanocrystals via thermal injection. ② Forming a Cs4PbCl6 shell nanocrystal on the CsPbCl3 nanocrystals. An oleic acid solution containing Cs is added to the CsPbCl3 nanocrystals; Cs ions tend to react with free Pb ions, and the Cs4PbCl6 shell nanocrystals grow epitaxially on the surface of the CsPbCl3 core nanocrystals. ③ Injecting a MnCl2 precursor into the pre-synthesized core-shell nanostructure at room temperature yields highly efficient Mn-emitting nanocrystals with promising applications in optoelectronics, generating significant social and economic benefits.

The present application relates to the technical field of escherichia coli drug resistance analysis, and particularly relates to a detection method for escherichia coli antibiotic resistance based on SERS and machine learning. The present application provides a detection method for escherichia coli antibiotic resistance based on SERS and machine learning to overcome the defects that high-precision and rapid diagnosis cannot be achieved in the prior art. The present application aims to utilize the core-shell nanostructure SERS substrate of silver-coated gold nanoparticles, combine the SERS spectrum differences of different phenotypic drug-resistant escherichia coli, and realize rapid and high-precision drug-resistant bacteria identification through machine learning algorithms. Through this method, the detection time can be significantly shortened, the detection accuracy can be improved, and accurate drug treatment plans can be provided for the clinic, which has a wide application prospect.

The invention discloses a preparation method of a core-shell-surface ternary heterostructure nano material with enhanced thermoelectric catalytic activity, and belongs to the technical field of nano functional materials and preparation thereof. The problems that in an existing metal / semiconductor composite material, the interface structure level is single, the carrier migration behavior is difficult to effectively regulate and control under the thermoelectric or photo-thermal-thermoelectric driving condition, and the precious metal modification stability is insufficient are solved. The technical defects that a traditional semiconductor material is low in energy utilization efficiency and limited in interface reaction regulation and control capacity under the thermal excitation condition are overcome. The method comprises the following steps: 1, preparing CZTS nanocrystals; 2, preparation of the Au-coated CZTS NPs core-shell nano structure material; (3) preparation of the Au-coated CZTS-Pt heterostructure nano material; and 4, modifying the nano material. The method is used for preparing the core-shell-surface ternary heterostructure nanometer material with the enhanced thermoelectric catalytic activity.

The invention discloses a WO3-coated FeWO4 core-shell nanostructure, a preparation method and application of the WO3-coated FeWO4 core-shell nanostructure in rice quality detection. The method comprises the following steps: by taking a WO3 nanorod formed by a traditional hydrothermal method as a core, regulating and controlling the types and doses of dopamine hydrochloride, a template agent and a buffer solution as well as the ratio of deionized water to ethanol in the solution, thereby obtaining the dopamine-coated WO3 nanorod; a catechol group in a dopamine molecule and iron ions are subjected to a coordination reaction to form an iron-dopamine complex, and the iron-dopamine complex is calcined to obtain the core-shell nanostructure (WO3-FeWO4) with the WO3 nanorod uniformly coated with FeWO4. According to the preparation method disclosed by the invention, the strong coordination chelation capability of dopamine hydrochloride is utilized, and the WO3-coated FeWO4 core-shell nanostructure is formed after controlling the atmosphere and the temperature in a calcining stage, and the prepared heterostructure exposes more crystal boundaries and defect sites; and the catalyst has good selectivity and excellent stability on a representative volatile metabolite 2-undecanone during rice aging at a working temperature of 260 DEG C.

The application provides a kind of Ag-based composite nanomaterial SERS utility determination method for dangerous chemicals, belong to the technical field of data processing of dangerous chemicals, the method includes: preparation Au nanocrystalline seed and Au@Ag core-shell nanostructure, preparation CeO2 nano cube and Ag-CeO2 nano heteropolymer, the Au@Ag core-shell nanostructure and the Ag-CeO2 nano heteropolymer are mixed to prepare surface enhanced raman detection substrate, by the detection substrate and raman spectrometer, raman spectrum standard correction matrix, substrate enhancement effect evaluation matrix, SERS enhancement coefficient correction matrix are acquired, and SERS signal intensity normalization matrix is established, finally through the SERS signal intensity normalization matrix, the substrate enhancement effect evaluation matrix and the raman spectrum standard correction matrix calculate SERS utility value, the application solves the technical problem that the accuracy of dangerous chemical SERS detection in the prior art is not high enough.