Multi-mode intelligent sensing system based on plasmon periodic structure, detection method and application

Abstract

The invention discloses a multi-mode intelligent sensing system based on a plasmon periodic structure, a detection method and application, and belongs to the field of intelligent materials and state monitoring. The core of the invention is to construct a periodically arranged plasmon sensing unit array, and the array simultaneously has dual functions of chemical sensing and vibration sensing. A system main body is of a periodic structure, and a plasmon functional unit with silver nanoparticle-TMB as a core is embedded in the periodic structure. When a target chemical substance in the environment triggers a plasmon-catalyzed TMB diazotization reaction, the unit generates a remarkable colorimetric and surface-enhanced Raman scattering signal to realize chemical sensing. Meanwhile, the chemical reaction can cause micro-change of local mechanical properties of the functional unit, so that the vibration transmission characteristic of the whole periodic structure is modulated. By monitoring the collaborative change of optical signals and mechanical signals in real time, the system can synchronously realize high-sensitivity detection of a chemical environment and evaluation and control of a broadband vibration state in situ.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of analytical chemistry and sensor technology, in particular to a dual-mode sensor based on plasmonic catalysis effect, and especially to a sensor for precisely regulating TMB diazotization reaction process by pH value of the system and realizing synchronous output of colorimetric and SERS signals, and a construction method and application thereof. BACKGROUND

[0002] In the fields of aerospace, ship, and precision chemical industry, the operation safety of liquid-filled pipeline systems (such as fuel pipes, hydraulic pipes, and cooling pipes) is of great importance. These systems face two major challenges: first, the wideband mechanical vibration and noise caused by fluid pressure pulsation and equipment vibration affect the accuracy and service life of the equipment; second, the chemical state changes of the medium in the pipeline (such as corrosion product accumulation, fuel degradation, and cooling liquid deterioration) are difficult to monitor in real time and in situ, which easily leads to sudden failures.

[0003] Currently, vibration control and chemical detection are usually two independent technical fields. For vibration control, liquid-filled periodic pipelines are based on phononic crystal / bandgap theory, and by periodic structure design, a bandgap is generated in a specific frequency range, thereby effectively suppressing vibration transmission, especially showing advantages that traditional vibration isolators cannot match in the low frequency band. For chemical detection, although the dual-mode sensor based on TMB plasmonic catalysis has high sensitivity, it is usually used as an independent and external detection element and cannot be integrated with the pipeline structure itself to realize in-situ and online monitoring.

[0004] If a technology can be developed to "weave" sensitive chemical sensing functions into the vibration control structure of the pipeline, the pipeline will not only be a passive vibration reduction channel, but also a "smart skin" that can perceive the internal chemical environment, which will greatly improve the state perception ability and intelligent level of the key system. However, how to effectively couple these two functions instead of simply adding them together and solve the negative impact of the sensing unit on the vibration control performance is a difficult problem that existing technologies have not been able to solve. SUMMARY

[0005] The present application aims to overcome the shortcomings of the prior art and provide a multi-mode intelligent sensing and vibration control system and method based on plasmonic periodic structure. The system achieves deep integration and functional synergy of physical vibration control and chemical information perception by skillfully integrating a plasmonic sensing unit in a liquid-filled periodic pipeline, achieving a "1+1>2" effect.

[0006] To achieve the above-mentioned purpose, the present application adopts the following technical solutions: A multi-mode intelligent sensing system based on plasmonic periodic structure, comprising: The sensing system is composed of a plasmonic periodic structure, a reaction substrate and a sample to be detected; the plasmonic periodic structure is composed of silver nano-materials, which are used as an active substrate and a sensing unit; the reaction substrate is 3,3',5,5'-tetramethylbenzidine (TMB), which is combined with the plasmonic periodic structure to form Ag-TMB. The regulatory factor is added to the sensing system, and is used for regulating the TMB diazotization reaction on the surface of the plasmonic periodic structure through hydrogen ions The concentration of the regulatory factor is adjusted. The detection unit includes an ultraviolet-visible spectrophotometer for collecting colorimetric signals and a confocal Raman spectrometer for collecting SERS signals; the unit is used for synchronously or selectively monitoring the optical signal changes of the sensing system in the process of the plasmonic catalytic reaction, and realizing cross verification and comprehensive analysis of the target analyte by correlating the colorimetric signals and the SERS signals, so as to finally realize multi-mode intelligent sensing.

[0007] Preferably, the pH value of the Ag-TMB is adjusted to be in the range of 2.0 to 5.0, so as to realize optimization of the reaction rate and the optical signal intensity.

[0008] Preferably, the plasmonic periodic structure is a periodic silver nanoparticle array.

[0009] A detection method using the multi-mode intelligent sensing system based on the plasmonic periodic structure, comprising the following steps: S1: integrating the reaction substrate, the sample to be detected and the plasmonic periodic structure to form a sensing system; S2: adjusting the pH value of the system by adding an acid, and exciting the plasmonic periodic structure to start the plasmonic catalytic TMB diazotization reaction; S3: synchronously or selectively obtaining the colorimetric signals and the SERS signals of the reaction system by the detection unit; S4: qualitatively or quantitatively analyzing the target analyte based on the changes and correlation of the colorimetric signals and the SERS signals, and evaluating the response state of the system.

[0010] Preferably, in step S2, the plasmonic periodic structure is excited by laser irradiation.

[0011] Preferably, the target analyte is an acidic or alkaline substance capable of changing the pH value of the reaction system.

[0012] An application of the detection method in environmental water quality monitoring, chemical process monitoring or intelligent sensing associated with physical states.

[0013] The present application has the following advantages: 1. Deep interdisciplinary and functional integration: The band gap regulation theory of phononic crystals is deeply integrated with plasmonic chemical sensing technology for the first time, creating an intelligent structure with both vibration control and chemical sensing capabilities, which is extremely creative.

[0014] 2. Bidirectional coupling and synergistic enhancement: The bidirectional information flow of "chemical stimulation → optical / mechanical response → system state evaluation" is realized. Chemical sensing provides a new monitoring dimension for vibration control state, while the flow field stability brought by vibration control also helps to improve the accuracy and reliability of sensing.

[0015] 3. Multi-mode, high-reliability sensing: Provides three independent signal reading modes of colorimetric, SERS and vibration transmission characteristics, and the information is cross-checked to significantly improve the reliability and accuracy of state monitoring.

[0016] 4. In-situ, online, intelligent: The sensing function is built into the structure body, realizing in-situ and online monitoring of the internal chemical environment of the pipeline, providing data support for predictive maintenance and intelligent decision-making. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 : In the embodiment of the application, the ultraviolet-visible absorption spectrum of TMB under different pH conditions (2-12) is shown.

[0018] Figure 2 : In the embodiment of the application, the ultraviolet-visible absorption spectrum of TMB and silver nanoparticles (Ag NPs) under different pH conditions (2-5) is shown.

[0019] Figure 3 : In the embodiment of the application, the SERS spectrum of TMB under different substrates (Ag, Au) and 633 nm laser excitation is shown.

[0020] Figure 4 : The regulation based on pH makes TMB get excited under Ag substrate.

[0021] Figure 5 : The system (such as ) triggers the plasmonic catalytic reaction in the trigger unit to produce colorimetric / SERS signal graphs. DETAILED DESCRIPTION

[0022] In order to better understand the technical solutions of the application, specific embodiments will be further described in detail, but the solutions are not limited thereto.

[0023] Embodiment 1: Multi-mode intelligent sensing system based on plasmonic periodic structure

[0024] 1. Materials and "periodic structure" system construction: Silver nanoparticle sols were prepared and then assembled onto a substrate to form a quasi-periodic ordered array using self-assembly or a template method. This ordered structure serves as the plasmonic periodic structure framework for this system, aiming to provide uniform and reproducible enhanced hotspots.

[0025] Prepare an ethanol stock solution of TMB as a reaction substrate.

[0026] The pH value of the system was adjusted by using hydrochloric acid (HCl) solutions of different concentrations as regulating factors.

[0027] The detection unit includes a UV-Vis spectrophotometer for colorimetric signal acquisition and a confocal Raman spectrometer. The confocal Raman spectrometer is equipped with a 633 nm laser and is used for SERS signal acquisition and spectroscopic monitoring of system status.

[0028] 2. Validation of pH regulation effect and multi-mode signal output, corresponding to Figure 1 , Figure 2 and Figure 5 : TMB solution was applied to the aforementioned quasi-periodic Ag NPs array, and the system was adjusted to different pH values, such as 2.0, 3.0, 4.0, and 5.0, with HCl.

[0029] The periodic structure was irradiated with a 633 nm laser to excite the plasmon effect.

[0030] Observations and Results: Colorimetric signals, such as Figure 5 The study found that within the pH range of 2.0-3.0, the color of the entire periodic structure region changed from colorless to yellow, and characteristic absorption peaks of oxTMB appeared near 430 nm, 447 nm, and 461 nm. This demonstrates the precise regulatory role of pH on the reaction process and showcases a macroscopic and visualized sensing mode.

[0031] Reaction mechanism, such as Figure 5 As shown: This process verifies the mechanism described in the schematic diagram. Under the stable enhancement field provided by the periodic structure, in an acidic environment... As a smart switch, it efficiently drives the diazotization reaction of TMB by regulating the utilization efficiency of hot electrons.

[0032] 3. Verification of SERS signal and system specificity, corresponding to Figure 3 And Figure 4: SERS scans were performed on the aligned periodic Ag NPs array under optimal pH conditions (e.g., pH=3.5).

[0033] The results are as follows Figure 4The typical characteristic peaks of oxTMB (e.g. ~1390 cm ¹, ~1590 cm ¹) can be stably observed on each unit of the periodic structure, which proves the consistency and high spatial resolution of the system response. In contrast, the disordered Ag NPs or Au NPs substrate does not work well, as shown in Fig. 5b, highlighting the importance of periodic structure design for signal stability and repeatability. Figure 3

[0034] Condition optimization: By comparing different laser wavelengths, it is determined that the 633 nm laser has a better excitation effect on the periodic structure system, and the system working parameters are optimized.

[0035] 4. Intelligent sensing and application examples: The system can be directly used for sensitive monitoring of water pH. By simultaneously collecting the periodic colorimetric signal and SERS signal, and establishing the quantitative relationship with pH value, multi-mode, self-verification intelligent sensing is achieved. Colorimetric is used for rapid screening, and SERS is used for accurate quantification and confirmation.

[0036] The system shows how to convert chemical stimuli into stable and reliable multi-mode optical signal output through an ordered plasmonic structure, providing a solid foundation for state monitoring and intelligent sensing in complex environments.​

Claims

1. A multi-mode intelligent sensing system based on plasmon periodic structure, characterized in that, include: The sensing system consists of a plasmonic periodic structure, a reaction substrate, and a sample to be tested. The plasmonic periodic structure is made of silver nanomaterials, which serve as the active substrate and sensing unit. The reaction substrate is 3,3',5,5'-tetramethylbenzidine (TMB), which combines with the plasmonic periodic structure to form Ag-TMB. Regulatory factor: Added to the sensing system to detect hydrogen ions Concentration-controlled TMB diazotization reaction on the surface of plasmon periodic structures; Detection unit: includes a UV-Vis spectrophotometer for acquiring colorimetric signals and a confocal Raman spectrometer for acquiring SERS signals; This unit is used to simultaneously or selectively monitor the changes in optical signals generated by the sensing system during the plasmonic catalytic reaction, and to achieve cross-validation and comprehensive analysis of the target analyte by correlating the colorimetric signal with the SERS signal, ultimately realizing multi-mode intelligent sensing.

2. The multi-mode intelligent sensing system based on a plasmonic periodic structure according to claim 1, characterized in that, By adjusting the pH value of the Ag-TMB within the range of 2.0 to 5.0, the reaction rate and optical signal intensity can be optimized.

3. The multi-mode intelligent sensing system based on a plasmonic periodic structure according to claim 1, characterized in that, The plasmon periodic structure is a periodically arranged array of silver nanoparticles.

4. A detection method using the multi-mode intelligent sensing system based on plasmon periodic structure as described in any one of claims 1-3, characterized in that, Includes the following steps: S1: Integrate the reaction substrate, the sample to be tested, and the plasmonic periodic structure to form a sensing system; S2: By adding acid to adjust the pH of the system and activating the plasmonic periodic structure, the plasmonic-catalyzed TMB diazotization reaction is initiated; S3: The colorimetric signal and SERS signal of the reaction system are acquired simultaneously or selectively through the detection unit; S4: Based on the changes and correlations of colorimetric and SERS signals, perform qualitative or quantitative analysis of the target analyte and evaluate the system's response status.

5. The detection method according to claim 4, characterized in that, In step S2, the plasmonic periodic structure is excited by laser irradiation.

6. The detection method according to claim 4, characterized in that, The target analyte is an acidic or alkaline substance that can change the pH of the reaction system.

7. The application of the detection method according to any one of claims 4-6 in environmental water quality monitoring, chemical process monitoring, or intelligent sensing associated with physical states.

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