Gold-silver-chromium nano composite material as well as preparation method and application thereof

Abstract

The invention discloses a gold-silver-chromium nano composite material as well as a preparation method and application thereof. The Au-Ag-CrNCs synthesized by a simple and efficient method not only can be used for colorimetric sensing of multiple modes and multiple analytes, but also plays an important role in the field of advanced MIT. Au-Cr nano seeds are generated through a pre-reaction, and the nano seeds are mixed with Ag < + >, a stabilizer SDBS and a reducing agent AA, so that Au-Ag-Cr NCs coated with the SDBS is successfully prepared. The morphological characteristic of the Au-Ag-Cr NCs is Au / Ag nanoparticles attached to the branched chromium nanobelt. The Au-Ag-Cr NCs can selectively and quantitatively detect two analytes (Hg < 2 + > and ClO <->) by analyzing the multi-signal change of color, Tyndall effect and absorption. Furthermore, a basic logic gate and an advanced logic circuit can be constructed by using the different substances as inputs and the signal change of the generated solution as an output. Meanwhile, through binary conversion of multi-signal response, molecular information coding, encryption and steganography based on Au-Ag-CrNCs logic relation and selective response can be realized.

Description

Technical Field

[0001] This invention relates to composite materials, specifically to a gold-silver-chromium nanocomposite material, its preparation method, and its applications. Background Technology

[0002] Multimetallic nanomaterials (MNMs) are composite materials composed of two or more metals, attracting widespread attention due to their unique physical, chemical, optical, and electrical properties. These materials combine the characteristics and advantages of each component, exhibiting significant synergistic effects that outperform single-metal nanomaterials and introduce novel performance characteristics. For example, bimetallic nanomaterials containing noble metal components (such as Au-Ag, Pt-Pd, and Au-Pt) have become a research hotspot due to their excellent catalytic performance and optical properties. With further research, trimetallic nanomaterials, as an extension of bimetallic nanomaterials, further enhance material performance and broaden their application range by introducing a third metal element. Due to the diversity of their composition and structure, these materials exhibit more complex physicochemical properties, providing new possibilities for applications in sensing, catalysis, and information science. The expansion of these applications depends not only on the properties of the materials themselves but also closely on their preparation methods. Currently, the main preparation methods for MNMs include seed-mediated growth, multimetal diffusion strategies, and guest species encapsulation strategies. Seed-mediated growth, as a bottom-up construction strategy, has been widely used due to its versatility, simplicity, and convenience. However, considering the complexity of different metal composition combinations and their impact on material structure and properties, proposing new manufacturing paradigms is particularly important. This will not only accelerate the development of novel metallurgical membrane materials (MNMs) but also support innovation in related application scenarios.

[0003] Life, as a complex entity, exhibits highly complex networks of molecular interactions and biochemical reactions. Biological systems in nature, particularly bees, ants, and birds, provide valuable insights through molecular coding and information transmission (such as pheromones). Inspired by these powerful collaborations and subtle operations based on complex molecular networks, scientists are striving to develop new artificial molecular or nanosystems for efficient sensing, programmable control, and molecular information technology (MIT). MIT, as an emerging frontier, encompasses multiple aspects of molecular information processing (such as logic computing), information storage (such as DNA data storage), and information security. The rapid development of these technologies relies on the scalable design and stimulus-response properties of molecular or nanosystems. Existing research has successfully demonstrated the potential of these systems in various applications, including sensing, logic computing, and information protection. By combining and sequencing input and output operations, molecular logic devices, such as basic logic gates, fuzzy logic, half-adders, full adders, parity generators / checkers, keypad locks, and even reversible logic, can be constructed to meet the growing demands for computational complexity. How to utilize simple molecular or nanosystems to construct large-scale parallel logic circuits and implement complex logic operations has become a direction worthy of in-depth exploration. For example, by exploring the multi-channel and multi-material sensing capabilities of molecular or nanosystems, the number of logical inputs and outputs can be significantly increased, thereby expanding the scale of logical operations. Simultaneously, another emerging research direction is how to develop or utilize molecular or nanosystems to explore the molecular information features they contain and achieve information protection (such as information encryption and hiding). Recently, some organic molecules, polymers, biomolecules, and nanomaterials have been creatively used for encoding, encrypting, and hiding information to achieve data storage and security (including molecular keypad locks, molecular authentication, cryptography, or steganography). The inherent chemical properties (color, absorption, or fluorescence spectra) and / or unique structures (such as DNA or polymeric sequences) of these (biological) molecules provide potential opportunities for developing multi-layered security technologies (including access, information encryption, and hiding). Nevertheless, there is still considerable room for research in deeply studying the properties and effects of different components in nanomaterials, exploring the diversification and updating of nanomaterial preparation paradigms, and applying molecular information beyond sensing functions. In particular, innovation remains lacking in expanding new stimulus-response mapping relationships and developing new molecular information encoding paradigms (including available molecular features, relationships, or response signals). These fields not only point to new directions for future technological development, but also provide fertile ground for exploring more possibilities. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention employs a simple, rapid, and efficient method to synthesize a multifunctional trimetallic gold-silver-chromium nanocomposite material (Au-Ag-CrNCs), which has been applied in multi-mode and multi-analyte sensing, advanced arithmetic and reversible logic, and long text information protection.

[0005] The technical solution of the present invention includes: a method for preparing a gold-silver-chromium nanocomposite material, characterized in that it is prepared at room temperature by Au-Cr nanoseed method, ascorbic acid reducing agent and sodium dodecylbenzenesulfonate stabilizer.

[0006] The above preparation method specifically includes: mixing Cr sequentially in an ice bath. 6+ Au 3+ Au-Cr nanoseeds were prepared by reacting with NaBH4 for 15 minutes, then allowed to stand at room temperature for 15 minutes, and then centrifuged and resuspended. The preparation steps for ternary materials based on Au-Ag nanoseeds and Ag-Cr nanoseeds were the same. Next, 250 μL of Au-Cr nanoseeds were mixed with 175 μL of 10 mM AgNO3 and 175 μL of 10 mM ascorbic acid at an Au ion to Cr ion concentration ratio of 1:2, and 400 μL of 10 mM SDBS was added to adjust the total liquid volume to 1000 μL. After reacting at room temperature for 70 minutes, the mixture was centrifuged and resuspended twice.

[0007] The present invention also discloses a gold-silver-chromium nanocomposite material prepared according to the above method.

[0008] This invention further discloses the use of gold-silver-chromium nanocomposites in Hg 2+ Detection, hypochlorite detection, and its application in information encryption.

[0009] This invention utilizes an Au-Cr nanoseed method, ascorbic acid reducing agent, and sodium dodecylbenzenesulfonate stabilizer to prepare and characterize trimetallic Au-Ag-CrNCs (Scheme 1B(a)) with Au / Ag nanoparticles at room temperature. Based on changes in color, Au / Ag plasma absorption, and their combined signal, Au-Ag-CrNCs exhibit Hg... 2+ and hypochlorite (ClO) - Highly sensitive and selective multimode colorimetric detection can be achieved, even in real water samples. This is attributed to the etching of Au / Ag nanoparticles in Au-Ag NCs by Hg2+ and ClO-. This contrasts with single-signal channels (such as ΔA). 530nm Compared to this, by cleverly integrating multiple signal channels (such as ΔA) 416nm *ΔA 530nm We significantly improved the response to Hg. 2+Selectivity (up to 3.32 times (ΔA)) 416nm *ΔA 530nm 12.03 times: ΔA 530nm (3.62 times) and sensitivity (up to 2,166.7 times (ΔA)) 416nm 39nM: ΔA 416nm *ΔA 700nm (0.018 nM) (Scheme 1B(a)), and selectivity for ClO- (up to 5.86 times (ΔA)). 416nm *ΔA 700nm 43.37 times: ΔA 416nm (7.40 times) and sensitivity (up to 1,653.8 times (ΔA)) 416n m of 43nM: ΔA 416nm *ΔA 700nm (0.026 nM) (Scheme 1B(b)). Furthermore, Au-Ag-CrNCs respond to the addition of different substances as input signals and generate multimodal colorimetric responses as outputs, providing new possibilities for developing batch and parallel multifunctional molecular logic, including basic logic gates, arithmetic, and reversible logic (Scheme 1C(a)). Based on this, through binary conversion and encoding of the inherent response of Au-Ag-CrNCs, we realized long-text molecular-level encryption and steganography based on molecular logic operations and multi-encoded selective responses, greatly enhancing the security and confidentiality of information (Scheme 1C(b)). This research not only opens up new avenues for the customized synthesis and diversified applications of multimetal nanocomposites but also provides new perspectives and opportunities for in-depth research into molecular or nanoscale information processing and protection technologies to achieve more powerful functions.

[0010] This invention synthesizes a multifunctional trimetallic gold-silver-chromium nanocomposite material (Au-Ag-Cr NCs) and utilizes its multimetallic plasmonic absorption properties for various applications, including multimode and multianalyte detection, advanced arithmetic operations and reversible logic, and long text information protection. Based on Au-Cr nanoseeds, Ag... + Au-Ag-CrNCs, containing Au / Ag nanoparticles and Cr nanoribbons, can be conveniently and rapidly prepared using ascorbic acid reducing agent and sodium dodecylbenzenesulfonate stabilizer. Au-Ag-CrNCs exhibit resistance to two analytes (Hg... 2+The multi-channel detection capability of Au-Ag-CrNCs (and hypochlorite) significantly improves selectivity and sensitivity when analyzing combined channels. The multiple responses of Au-Ag-CrNCs to different combinations of substances correspond to input-output mapping relationships, enabling the execution of various advanced molecular logic calculations (such as arithmetic and reversible logic). By digitizing its inherent sensing and response, advanced molecular information protection (encoding, encryption, and concealment) of long texts was successfully achieved. This research not only provides new ideas for the preparation and diversity of multi-component nanocomposites but also offers new insights into the emergence of novel molecular information technology paradigms, linking sensing, logic, and information. Attached Figure Description

[0011] Figure 1 Scheme 1A is a schematic diagram of the synthesis of multi-purpose trimetallic Au-Ag-Cr nanoclusters; Scheme 1B is for multi-mode and multi-analyte sensing; Scheme 1Ca is for advanced arithmetic and reversible logic; Scheme 1Cb is for long text information protection.

[0012] Figure 1A -O is the preparation, transmission electron microscopy (TEM) imaging, and energy-dispersive spectroscopy (EDS) elemental distribution characterization of .Au-Ag-Cr NCs. Figure 1A , Figure 1B The colors and Tyndall effect of different combined reaction solutions after resuspension at room temperature (RT) using one-pot reduction and nanoseeding methods. Figure 1A ) and absorption spectrum ( Figure 1B The concentrations of each ion in the reaction solution are as follows: Au 3+ 0.25mM, Cr 6+ 0.5mM, Ag + AA: 1.75 mM, SDBS: 4 mM. Note: This concentration ratio is not the final optimized result. Figure 1C Schematic diagram of Au-Ag-Cr NCs synthesis. Figure 1D Statistical histograms of the diameters of Cr nanospheres (N=101) and spherical Au / Ag nanoparticles (N=370) obtained by processing transmission electron microscopy (TEM) images using ImageJ software. Figure 1E , Figure 1F Light brown colloidal solution (corresponding to) Figure 1A , Figure 1B Transmission electron microscopy (TEM) images of group b in the image ( Figure 1E ) and its high-resolution transmission electron microscopy (HRTEM) analysis of lattice fringes ( Figure 1F (Figure GO) High-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) image of a light brown colloidal solution. Figure 1G ) and energy dispersive spectroscopy (EDS) elemental distribution map ( Figure 1H-1OThe scale bar is 100nm or 5nm.

[0013] Figure 2. Characterization of Au-Ag-CrNCs by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS). Figure 2A , Figure 2B X-ray diffraction (XRD) pattern (Figure A) and Fourier transform infrared (FTIR) pattern (Figure A) of Au-Ag-Cr NCs Figure 2B X-ray photoelectron spectroscopy (XPS) full spectrum of (CF)Au-Ag-CrNCs Figure 2C ) and Au 4f( Figure 2D Ag 3d (Figure E), Cr 2p ( Figure 2F The XPS core level spectrum. Figure 2G-2I C1s of Au-Ag-CrNCs Figure 2G ), O 1s( Figure 2H ) and S2p( Figure 2I XPS core level spectrum.

[0014] Figure 3. Effect of Au-Ag-CrNCs on Hg 2+ The selectivity. Figure 3A , Figure 3B The photograph shows the changes in color and Tyndall effect of Au-Ag-CrNCs solutions mixed with different metal ions. Figure 3A ), and the corresponding changes in absorption spectra ( Figure 3B ). ( Figure 3C-3E The changes in individual channels of Au-Ag-CrNCs after mixing with different metal ions, including the change in absorbance at 416 nm (ΔA). 416nm , Figure 3C ), absorbance change at 530 nm (ΔA) 530nm , Figure 3D ) and the change in absorbance at 700 nm (ΔA) 700nm , Figure 3E ). ( Figure 3F-3J The changes in the combined channels of Au-Ag-CrNCs after mixing with different metal ions, including ΔA 416nm ×ΔA 530nm ( Figure 3F ), ΔA 416nm ×ΔA 700nm ( Figure 3G ), ΔA 530nm ×ΔA 700nm ( Figure 3H ), SUMΔA (328-500nm) ( Figure 3I ) and SUMΔA (502-700nm) ( Figure 3JA0 and A represent the absorbance with and without the analyte, respectively. Au-Ag-Cr NCs were prepared at a concentration ratio of 0.25:1.75:0.5 mM and diluted 1.33 times. All metal ion concentrations: 100 μM.

[0015] Figure 4. Selectivity of Au-Ag-Cr NCs for ClO-. Figure 4A , Figure 4B Changes in color and Tyndall effect of anionic or reducing agent solutions mixed with Au-Ag-Cr NCs. Figure 4A ), and the corresponding changes in absorption spectra ( Figure 4B ). ( Figure 4C-4E Changes in individual signal channels after Au-Ag-CrNCs are mixed with different substances, including changes in absorbance at 416 nm (ΔA). 416nm The absorbance change at 4C and 530nm (ΔA) 530nm , Figure 4D ) and the change in absorbance at 700 nm (ΔA) 700nm , Figure 4E ). ( Figure 4F-4J Changes in the combined channels of Au-Ag-CrNCs after mixing with different substances, including ΔA 416nm ×ΔA 530nm ( Figure 4F ), ΔA 416nm ×ΔA 700nm ( Figure 4G ), ΔA 530nm ×ΔA 700nm ( Figure 4H ), SUMΔA (328-500nm) ( Figure 4I ) and SUMΔA (502-700nm) ( Figure 4J A0 and A represent the absorbance with and without the analyte, respectively. Au-Ag-CrNCs were prepared at a concentration ratio of 0.25:1.75:0.5 mM and diluted 1.33-fold. All anion / reducing agent concentrations: 100 μM. Figure 5. Multimode colorimetric method based on Au-Ag-CrNCs for the detection of Hg. 2+ . ( Figure 5A , Figure 5B Add different concentrations of Hg 2+ The color and Tyndall effect of Au-Ag-CrNCs (0.25:1.75:0.5mM, diluted 1.33 times) after (0~450μM) were captured in photographs. Figure 5A ), and the corresponding changes in absorption spectra ( Figure 5B Note: Each absorption spectrum was recorded 5 minutes after the reaction. Figure 5C-5H Add different concentrations of Hg2+ The single-channel response of Au-Ag-CrNCs (including absorbance changes at 416 nm, 530 nm, and 700 nm) Figure 5C , 5E (and 5G), and their corresponding linear calibration curves ( Figure 5D , 5F and 5H). Figure 5I-5N Add different concentrations of Hg 2+ The combined channel response of Au-Ag-CrNCs (including ΔA) 416nm ×ΔA 530nm ( Figure 5I ), ΔA 416nm ×ΔA 700nm ( Figure 5K ), ΔA 530nm ×ΔA 700nm ( Figure 5M ), SUMΔA (328-500nm) ( Figure 5O ) and SUMΔA (502-700nm) ( Figure 5Q )), and their corresponding calibration curves ( Figure 5J , 5L 5N, 5P, and 5R).

[0016] Figure 6. Detection of ClO- using a multimode colorimetric method based on Au-Ag-CrNCs. Figure 6A , Figure 6B Photographs showing the color and Tyndall effect of Au-Ag-CrNCs (0.25:1.75:0.5mM, diluted 1.33 times) after adding different concentrations of ClO- (0-450μM). Figure 6A ), and the corresponding changes in absorption spectra ( Figure 6B Note: Each absorption spectrum was measured 5 minutes after the reaction. Figure 6C-6J The single-channel response of Au-Ag-Cr NCs after adding different concentrations of ClO- was shown, revealing the absorbance changes at 416 nm, 530 nm, and 700 nm. Figure 6C , 6E and 6G) ​​and their corresponding linear calibration curves ( Figure 6D , 6F and 6H). Figure 6I-6R The combined channel responses of Au-Ag-CrNCs after adding different concentrations of ClO-, including ΔA 416nm ×ΔA 530nm ( Figure 6I ), ΔA 416nm ×ΔA 700nm ( Figure 6K ), ΔA 530nm ×ΔA 700nm ( Figure 6M ), SUMΔA (328-500nm) ( Figure 6O ) and SUMΔA (502-700nm) ( Figure 6Q ), and their corresponding calibration curves ( Figure 6J , 6L 6N, 6P, and 6R).

[0017] Figure 7. Au-Ag-Cr NCs and Hg 2+ Characterization of mixtures. Figure 7A , Figure 7C , Figure 7E-7M Au-Ag-Cr NCs and Hg 2+ Transmission electron microscopy (TEM) images of the mixture Figure 7A High-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) images Figure 7C ) and energy dispersive spectroscopy (EDS) elemental distribution map ( Figure 7E-7M , Figure 7E - Distribution map of all elements Figure 7F -Au, Figure 7G -Ag, Figure 7H -Cr, Figure 7I -Hg, Figure 7J -B, Figure 7K -N, Figure 7L -O, Figure 7M -S). ( Figure 7B Statistical histograms of the diameters of spherical Au / Ag nanoparticles in the mixture, obtained by processing transmission electron microscopy (TEM) images using ImageJ software. Figure 7D Add Hg to Au-Ag-CrNCs 2+ A schematic diagram of the post-state change. The scale bar is 100nm or 50nm.

[0018] Figure 8. Characterization of the mixture of Au-Ag-Cr NCs and ClO-. Figure 8A , Figure 8C , Figure 8E-8M Transmission electron microscopy (TEM) images of a mixture of Au-Ag-CrNCs and ClO- Figure 8A High-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) images Figure 8C ) and energy dispersive spectroscopy (EDS) elemental distribution map ( Figure 8E-8M , Figure 8E - Distribution map of all elements Figure 8F -Au, Figure 8G -Ag, Figure 8H -Cr, Figure 8I -Cl, Figure 8J -B, Figure 8K -N, Figure 8L -O, Figure 8M -S). ( Figure 8B Statistical histograms of the diameters of spherical Au-Ag nanoparticles in the mixture, obtained by processing transmission electron microscopy (TEM) images using ImageJ software. Figure 8D A schematic diagram illustrating the state changes after adding ClO- to Au-Ag-CrNCs. Scale bar is 50 nm.

[0019] Figure 9. Parallel and batch molecular logic computation based on Au-Ag-Cr NCs. Figure 9A A schematic diagram illustrating the input-output relationships of simple logic gates and complex logic circuits constructed based on Au-Ag-Cr NCs. Figure 9B-9D This involves multi-mode simple logic gates and complex cascaded circuits based on nine-signal outputs from Au-Ag-Cr NCs. The thresholds are defined as follows: "purple", A 264nm >1.10( Figure 9B ), 1.10 Figure 9C ), 1.16 ( Figure 9D );|ΔA 264nm |>0.10( Figure 9B ), 0.03 Figure 9C ), 0.10 ( Figure 9D A 332nm >0.77( Figure 9B ), 0.82 Figure 9C ), 0.85 Figure 9D );|ΔA 332nm |>0.03( Figure 9B ), 0.04 Figure 9C ), 0.06 Figure 9D A 416nm >0.90 (Figure B), 0.92 ( Figure 9C ), 0.80 Figure 9D );|ΔA 416nm |>0.20 (Figure B), 0.17 ( Figure 9C ), 0.10 ( Figure 9D A 530nm >0.90( Figure 9B ), 0.94 Figure 9C ), 0.90 Figure 9D );|ΔA 530nm |>0.02( Figure 9B ), 0.03 Figure 9C ), 0.06 Figure 9DDefined as "1" otherwise as "0". Au-Ag-CrNCs: 0.25:1.75:0.50 mM, diluted 1.33 times. GSH and H2O2: 10 mM, Hg 2+ ClO-: 60μM.

[0020] Figure 10. Molecular information encoding, cryptography, and steganography based on the logical relationships and selective responses of Au-Ag-CrNCs. Figure 10A A basic hybrid model of cryptography and steganography, including reversible encryption-decryption and steganography processes. Figure 10B Au-Ag-CrNCs are used for multi-signal selective responses in molecular steganographic cryptography. (a) Au-Ag-CrNCs (as the steganographic object) sense 19 metal ions or 13 anions / reducing agents (as the steganographic key) to generate multi-signal outputs (ΔA, ΔA*ΔA, and SUMΔA). (b) The steganographic analysis process decodes the selective responses to obtain the hidden information, represented as sixteen lines of 19-bit and 13-bit binary strings based on arbitrary thresholds. (c) A schematic diagram of the basic rules for splitting the binary string and the encoded information. (d) Two examples (e.g., 1, 2) illustrate the decryption process using the correct key to retrieve the secret information. The yellow text boxes explain the meaning of the secret information. Figure 10C The input-output logic of molecular steganography based on Au-Ag-CrNCs. (a) Au-Ag-CrNCs (as the steganographic object) receive input stimuli (metal ions or active reagents as steganographic keys) and generate multiple response outputs (color, A) 264nm ,|ΔA 264nm |,A 332nm ,|ΔA 332nm |,A 416nm ,|ΔA 416nm |,A 530nm and |ΔA 530nm |). (b) The steganalysis process decodes the Au-Ag-CrNCs-based logical operations to obtain 12 lines of hidden information represented as 8-bit binary output (from Figure 9B -D). (c) The decryption process uses the key to retrieve the corresponding secret information ("Live like you're going to die tomorrow."). Detailed Implementation

[0021] The present invention will now be described in detail with reference to the embodiments.

[0022] 1.1 Experimental Materials and Reagents

[0023] Potassium dichromate (K₂Cr₂O₇), potassium tetrachloroaurate (KAuCl₄), silver nitrate (AgNO₃), sodium hydride (NaBH₄), ascorbic acid (AA), and sodium dodecylbenzenesulfonate (SDBS) were all purchased from Aladdin Biochemical Technology Co., Ltd. (Shanghai, China). All aqueous solutions were prepared using ultrapure water produced by the Milli-Q system (Millipore, USA), with a resistivity of 18.2 MΩ·cm.

[0024] 1.2 Preparation and purification of gold-silver-chromium nanocomposites

[0025] Based on the optimized reaction conditions, the preparation steps are as follows. First, Cr is sequentially mixed in an ice bath. 6+ Au 3+ Au-Cr nanoseeds were prepared by reacting with NaBH4 for 15 minutes, then allowed to stand at room temperature for 15 minutes, and finally centrifuged and resuspended. The preparation steps for Au-Ag or Ag-Cr nanoseeds were the same. Next, 250 μL of Au-Cr nanoseeds (1:2 mM), 175 μL of AgNO3 (10 mM), and 175 μL of AA (10 mM) were sequentially added to 400 μL of SDBS (10 mM), adjusting the total liquid volume to 1000 μL. Each reactant was mixed 3-5 times with a pipette to ensure thorough mixing. After reacting at room temperature for 70 minutes, the mixture was centrifuged and resuspended twice. The final concentration of Au-Ag-Cr NCs (0.25:1.75:0.5 mM) was defined by the final concentration of the metal elements added to the reaction.

[0026] 1.3 Gold-Silver-Chromium Nanocomposites and Their Relationship with Hg 2+ Characterization of mixtures of orthochloride

[0027] The absorption spectra of purified Au-Ag-CrNCs were measured using a SpectraMax M5 microplate reader (Molecular Devices, USA). The purified Au-Ag-CrNCs and their interaction with Hg were observed using a FEI Talos F200X transmission electron microscope (TEM, FEI, USA) equipped with an energy-dispersive spectroscopy (EDS) instrument. 2+ / ClO - The mixture was characterized using X-ray diffraction (XRD, Rigaku, Japan), an IS-50 Fourier transform infrared spectrometer (FTIR, Thermo Fisher Scientific, USA), and a 250Xi X-ray photoelectron spectroscopy (XPS, Thermo Fisher Scientific, USA).

[0028] 1.4 Hg based on Au-Ag-CrNCs 2+ or selective and quantitative detection of hypochlorite

[0029] Au-Ag-CrNCs can be used for the detection of two different types of analytes (metal ions and anions / reducing agents). Metal ions or anions / reducing agents (100 μM) were added to Au-Ag-CrNCs (0.25:1.75:0.5 mM, diluted 1.33 times), and after reacting for 5 minutes at room temperature, the color, Tyndall effect, and UV-Vis absorption spectra of the resulting solution were recorded. The single-channel absorbance change at specific wavelengths (the absorbance difference (ΔA) at 416, 530, and 700 nm) was calculated by subtracting the absorbance of Au-Ag-CrNCs alone from the absorbance of the mixture. 416nm ΔA 530nm and ΔA 700nm We further combine these changes (ΔA) under different channels. 416nm *ΔA 530nm ΔA 416nm *ΔA 700nm ΔA 530nm *ΔA 700nm SUMΔA (328-500nm) SUMΔA (502-700nm) To assess the improvement in selectivity and sensitivity, the selectivity of a specific channel was calculated using Hg. 2+ and ClO - The ratio of the response of the active ingredient to the second highest response of the interfering substance is used to determine this.

[0030] For Hg 2+ or ClO - For quantitative detection, we reacted Au-Ag-Cr NCs with Hg at concentrations ranging from 0 to 450 μM. 2+ or ClO - Mix. After 5 minutes of reaction, record the color, Tyndall effect, and UV-Vis absorption spectra. We analyze the signal changes in single-channel and combined-channel reactions with Hg. 2+ or ClO - Correlation between concentrations. The limit of detection (LOD) is calculated as three times the standard deviation of the blank signal divided by the slope of the standard curve.

[0031] 1.5 Sample Analysis

[0032] Samples of pool water and tap water were collected from the applicant's campus for Hg testing. 2+ or ClO - Spiking and recovery experiments were conducted. Samples were filtered through a 0.22 μm membrane and used to dilute standard Hg. 2+ or ClO - Solution. Hg of known concentration.2+ or ClO - The mixture was then added to an Au-Ag-CrNCs solution (0.25:1.75:0.5 mM, diluted 1.33 times). After 5 minutes of reaction, we detected and analyzed different signal channels in the mixed solution.

[0033] 1.6 Effects of Au-Ag-Cr-NCs on Hg 2+ and ClO - molecular logic operations of the response

[0034] By using different substances (such as Hg) 2+ ,ClO - By adding GSH or H2O2 to Au-Ag-CrNCs as input and using colorimetric changes (color, absorbance, and their absolute differences at 264, 332, 416, and 530 nm) in multiple signal channels as output, a series of basic logic gates and advanced cascaded logic circuits can be constructed. By mixing different combinations of substances and reacting at room temperature for 10 minutes, the color of the resulting solution and its original absorption spectrum can be photographed or measured. Finally, by setting appropriate thresholds, various Boolean logic gates or complex molecular logic circuits can be constructed.

[0035] 1.7 Molecular Encryption Steganography Based on Au-Ag-CrNC

[0036] In a molecular cryptographic steganography based on the selective response of Au-Ag-CrNCs, 19 metal ions or 13 anions / reducing agents (as steganographic keys) are introduced into Au-Ag-CrNCs (the steganographic object), evoking selective responses in single-channel and combined-channel applications. These response signals in eight channels are then converted into eight groups of 19-bit or 13-bit binary strings based on specific thresholds. These 19-bit or 13-bit binary strings are split into fourteen 6-bit or thirteen 7-bit strings (from the 19-bit string) and eight 6-bit or seven 7-bit strings (from the 13-bit string). Finally, these binary strings are deciphered into understandable information (the decrypted secret information) using a corresponding cipher table. All experimental operations follow the same procedure as those for Au-Ag-CrNCs selectivity.

[0037] In molecular cryptography based on Au-Ag-Cr NCs molecular logic operations, when different combinations of Hg are added... 2+ And GSH, or ClO - and H2O2, or Hg 2+ and ClO -When used as a steganographic key, the mixed solution as the steganographic object can produce multiple signal outputs (such as color, absorbance, and their absolute differences at 264, 332, 416, and 530 nm). Three truth tables (two inputs and nine outputs) can be generated through four combinations (Hg). 2+ And GSH, or ClO - and H2O2, or Hg 2+ and ClO - Then, the two inputs and nine outputs from the three truth tables are defined as C0, C1, C2, and C3, respectively. By combining C0+C1+C2, C0+C2+C3, and C0+C3+C1, three sets of 12-line 8-bit binary strings can be generated to encode more information. By consulting the relevant cipher table, these binary strings are interpreted as understandable decrypted information. All experimental procedures are similar to those in molecular logic gates based on Au-Ag-CrNCs.

[0038] 2. Results and Discussion

[0039] 2.1 Preparation and characterization of Au-Ag-CrNCs

[0040] To prepare Au-Ag-Cr NCs, we investigated the effects of two methods (one-pot reduction and nanoseed method) on the three metal ions (Au, Ag, and Cr) at different reaction temperatures (room temperature and 50°C heating), different reducing agents (ascorbic acid AA or sodium hydride NaBH4), and different stabilizers (sodium dodecylbenzenesulfonate SDBS). 3+ Ag + Cr 6+ The effect of mixed reactions. We evaluated the synthesis effect of Au-Ag-CrNCs by photographing and analyzing the color, Tyndall effect, and absorption spectra of mixed reaction solutions with different combinations. Under various combined conditions, only the Au-Cr nanoseed method using AA reducing agent and SDBS stabilizer at room temperature (i.e., first using Au...) 3+ and Cr 6+ The reaction of ions with NaBH4 to prepare Au-Cr NCs can produce a stable and homogeneous colloidal solution with characteristic absorption peaks of gold (approximately 536 nm) and silver (approximately 416 nm) nanomaterials. Figure 1A (b), Figure 1B (b)). And for Au 3+ Ag + Cr 6+ A direct mixture of Au-Ag nanoseeds or Ag-Cr nanoseeds, prepared at room temperature using AA reducing agent and SDBS stabilizer, produces either a clear solution without characteristic absorption peaks or only a single absorption peak from the gold nanomaterials. Figure 1A (a,c,d), Figure 1B(a,c,d)).

[0041] Under room temperature or 50°C heating conditions, using AA as a reducing agent and without adding a stabilizer, the Au-Cr nanoseed method only yielded characteristic absorption peaks for gold (approximately 530 nm) and silver (approximately 416 nm) nanomaterials. However, the resulting solution was unstable and precipitated after a period of time. Adding the stabilizer SDBS to the reaction significantly improved the stability of the colloidal solution. However, when AA was replaced with NaBH4, the characteristic absorption peaks of gold and silver nanoparticles (NPs) only became apparent at 50°C using the Au-Cr nanoseed method. Similarly, without the SDBS stabilizer, the colloidal solution readily precipitated rapidly, while the stability of the solution improved with the addition of SDBS. However, compared to NaBH4, AA promoted the reaction to obtain more NCs because its Au and Ag NPs had higher absorption peaks. Subsequently, we monitored the time-dependent process of synthesizing Au-Ag-CrNCs using the Au-Cr nanoseed method. Without SDBS, the mixed solution with AA as a reducing agent reacted completely within approximately 30 minutes, with precipitation beginning after 70 minutes, accompanied by a decrease in the characteristic absorption peak. In the presence of SDBS, the solution was stable between 30 and 90 minutes, with no significant color change after 70 minutes. In contrast, when NaBH4 was used as a reducing agent in conjunction with SDBS, the mixed solution required 270 minutes to maintain a stable color, and the characteristic absorption peak of AgNPs reached its maximum and then decreased. These results demonstrate that AA reducing agent can promote the synthesis of Au-Ag-Cr NCs at room temperature, and the presence of SDBS stabilizer further stabilizes the colloidal solution. Therefore, we chose the Au-Cr nanoseed method using AA reducing agent and SDBS stabilizer at room temperature to prepare Au-Ag-Cr NCs (steps 1 and 2). Figure 1C ).

[0042] In addition, we gradually changed Ag + The concentrations of AA and SDBS were gradually increased along a 0.25 mM gradient to explore the optimal addition concentrations. As shown, when the concentrations of AA (2 mM) and SDBS (3 mM) remained constant and Ag... +At a concentration of 1.75 mM, the solution exhibited the deepest color and highest absorbance values ​​at 416 nm and 530 nm. Similarly, following the steps described above, the concentrations of AA and SDBS varied along a gradient. When the AA concentration was 1.25 mM, the solution was even darker, and the two characteristic absorption peaks in the absorption spectrum were higher (considering that at an AA concentration of 2 mM, the characteristic peaks of Ag NPs and Au NPs did not show significant improvement, and the peak positions shifted considerably. To save costs, the final AA addition concentration was 1.25 mM). As shown, when the SDBS concentration was 3.75 mM, the solution was the darkest, and the two characteristic absorption peaks reached their highest levels. The characteristic absorption peaks of the subsequently mass-produced material stabilized at approximately 416 nm and 530 nm. Storage stability experiments revealed that although the absorption of the Au-Ag-CrNCs colloidal solution changed significantly after 10 hours of reaction, it remained essentially stable for the following 42 days (this is our provisional detection time point). Therefore, we used Au-Ag-Cr NCs after 10 hours of reaction for all relevant follow-up experiments to ensure their reliability and reproducibility in practical applications.

[0043] Transmission electron microscopy (TEM) characterization results showed that the obtained light brown colloidal solution mainly consisted of ribbon-like chromium nanoribbons (CrNBs), with an average diameter of 56.93 ± 2.77 mm. 2 =0.990, N=101), Figure 1D It consists of spherical gold / silver nanoparticles (Au / AgNPs) with an average diameter of 14.15 ± 0.63 (R). 2 =0.994, N=370), Figure 1D ) distributed on it ( Figure 1E High-resolution TEM analysis revealed that Au-Ag-CrNCs exhibited distinct lattice fringes with average spacings of 0.219, 0.238, and 0.251 nm, corresponding to the Ag(111) / Au(111) plane and the Ag(200) plane, respectively. Figure 1F Elemental mapping results from energy dispersive spectroscopy (EDS) indicate the presence of Au, Ag, Cr, B, N, O, and S elements in the synthesized Au-Ag-CrNCs. Figure 1G-1O Green AuNPs and red AgNPs dot the branched bands of CrNBs. Figure 1H-1J Since Au-Ag-CrNCs are prepared via the Au-Cr nanoseed method, Ag NPs are uniformly dispersed on the Au-Cr nanostructure. B and N elements are relatively uniformly distributed in the field of view. Figure 1L , Figure 1M This is attributed to the small amount of residual byproducts in Au-Ag-CrNCs. O and S elements are uniformly distributed across the entire surface of Au-Ag-CrNCs, indicating that SDBS is stably adsorbed on them. Figure 1N , Figure 10 ).

[0044] X-ray diffraction (XRD) analysis revealed diffraction peaks at 2θ = 38.10°, 44.30°, 64.54°, 77.56°, and 81.76°, corresponding to the (111), (200), (220), (311), and (222) planes of Au or Ag, respectively. The diffraction peaks at 2θ = 44.30° and 81.76° also corresponded to the (110) and (211) planes of Cr. Figure 2A ). Figure 2B FTIR analysis showed that 3420.62 cm -1 The vibrational peak at 2922.11 cm⁻¹ is attributed to the stretching vibrations of O–H molecules in the colloid. -1 and 2851.72cm -1 The peaks are attributed to the asymmetric and symmetric stretching of the –CH(CH2) group, respectively. (1630.04 cm⁻¹) -1 and 1406.82cm -1 The peaks correspond to the C=O stretching vibration of the carboxyl group and the OH bending of the carboxylate, respectively. Additionally, the peaks at 1184.08, 1130.08, and 1041.85 cm⁻¹ correspond to these vibrations. -1 The peak corresponds to the S=O stretching of the sulfonate –SO3– group. Due to interatomic vibrations, the FTIR peak of the oxide appears at 1000 cm⁻¹. -1 The following area, therefore 831.17cm -1 The peak is related to the Ag–O–C bond. The spectrum does not show approximately 753 cm⁻¹. -1 The presence of Ag–O peaks indicates that Ag may not have been oxidized in NCs. (673.04 and 581.91 cm⁻¹) -1 The peak corresponds to the tensile vibration of Cr–O in Cr2O3.

[0045] X-ray photoelectron spectroscopy (XPS) revealed that Au-Ag-CrNCs mainly contain six peaks: Cr 2p, O 1s, Ag 3d, C 1s, S 2p, and Au 4f. Figure 2C The high-resolution Au 4f core level spectrum can be decomposed into two main peaks, located at Au 4f. 7 / 2 (84.6eV) and Au 4f 5 / 2 (88.3eV), Au 4f 7 / 2 With Au 4f 5 / 2 The splitting energy between them is 3.7 eV, attributed to the zero-valent metal Au. The secondary peak at 86.0 eV indicates the presence of a very small amount of gold in the form of Au(III). Figure 2DThe high-resolution core level spectrum of Ag 3d shows four peaks, which can be decomposed into Ag 3d... 5 / 2 (368.5eV) and Ag 3d 3 / 2 The peaks at (374.5 eV) 62 and 63, with a splitting energy of 6.0 eV, indicate the presence of metallic Ag. Furthermore, the three secondary peaks at 367.3, 369.0, and 373.7 eV can be attributed to Ag₂O (…). Figure 2E The high-resolution core level spectrum of Cr 2p includes five decomposition peaks at 577.5, 578.8, 586.9, 588.1, and 589.6 eV. These peaks can be decomposed into Cr 2p. 3 / 2 (577.5 eV) and Cr 2p 1 / 2 The Cr(III) peaks at (586.9 and 588.1 eV) correspond to the characteristics of Cr₂O₃. The two peaks at 578.8 and 589.6 eV can be decomposed into Cr(VI) peaks and Cr 2p. 3 / 2 and Cr 2p 1 / 2 ( Figure 2F The C 1s core level spectrum can be decomposed into a main peak at 284.8 eV and a secondary peak at 285.9 eV, corresponding to CC and COH at 69 and 70 eV, respectively. Figure 2G The core energy level spectrum of O 1s can be decomposed into three peaks at 531.7, 533.0, and 533.9 eV, which are attributed to -OH / adsorbed oxygen (531.7 eV), CO (533.0 eV), and adsorbed water (533.9 eV), respectively. Figure 2H The core energy level spectrum of S2p can be decomposed into three peaks at 168.2, 169.4, and 170.1 eV, which are attributed to the S2P in the sulfonate group. 3 / 2 and S2P 1 / 2 This indicates the presence of SDBS molecules and / or DBS in Au–Ag–CrNCs. - Group ( Figure 2I The characterization results above indicate that the prepared ternary metal nanomaterials are mainly Au–Ag–CrNCs.

[0046] To test the selectivity of Au-Ag-Cr NCs for specific analytes, Au-Ag-Cr NCs were mixed with two target substances, including (1) 19 metal ions: Hg 2+ Pb 2+ Ni 2+ Cr 3+ Al 3+ Fe 3+ Ba 2+ Mg 2+ Mn 2+ Ca 2+ K+ Zn 2+ Cu 2+ Na + Cd 2+ Ag + Fe 2+ (2) 13 kinds of anions / reducing agents: ClO - H2O2, I - AC - PO4 3- Cl - HCO3 - OH - H2PO4 - DA, AA, Br - ClO4 - (All concentrations were 100 μM). After reacting for 5 minutes at room temperature, we recorded the color, Tyndall effect, and UV-Vis absorption spectra of the mixed solutions. Figure 3A As shown, among the 19 metal ions tested, Hg... 2+ The color of the Au-Ag-CrNCs solution changed from light brown to light purple. Figure 3A Meanwhile, the absorption at 416nm and 530nm decreased significantly. Figure 3B In contrast, other interfering metal ions did not show significant selectivity compared to the blank control in terms of solution color, Tyndall effect, or absorption spectrum; only Fe3+ caused a slight color change and a decrease in the absorption band at 416 nm. Figure 3A , Figure 3B ).

[0047] Initially, we selected three specific wavelengths (at 416 nm (ΔA)). 416nm ), 530nm (ΔA) 530nm ) and 700nm (ΔA 700nm (Absorption differences) Further comparison of Hg 2+ Response to other interfering metal ions. Figure 3C-3E The results show that Au-Ag-CrNCs affect Hg in these three channels. 2+ The absorption response is most significant (ΔA) 416nm =0.454au, ΔA 530nm =0.170au, ΔA 700nm=0.088au), these values ​​are at least 3.34, 3.62, and -1.85 times that of other interfering metal ions (because the interference response is greater than zero). To reveal hidden features in the response changes, enhance the signal-to-noise ratio between the target analyte and the interfering analyte, and improve detection sensitivity, we chose to combine absorption at different wavelengths for comprehensive analysis. Through combined channel analysis, we found that the combined channel can significantly enhance the detection of Hg. 2+ The selectivity and sensitivity compared to single-channel detection. For example... Figure 3F As shown in -H, the combined absorption changes at two fixed wavelengths yielded ΔA. 416nm *ΔA 530nm ΔA 416nm *ΔA 700n m and ΔA 530nm *ΔA 700nm In these three binding channels, Hg 2+ The changes were 0.077, 0.040, and 0.015 au, respectively, which were at least 12.03, 6.90, and 7.50 times higher than those of other metal ions. Furthermore, the summation of absorption changes across different wavelength ranges yielded SUMΔA. (328-500nm) and SUMΔA (502-700nm) The changes in Hg2+ in these two binding channels were 25.23 and 17.51 ​​au, respectively, which are at least 4.41 and 3.00 times higher than those of other metal ions. Figure 3I , Figure 3J These results indicate that combining the two channels can significantly enhance the response to Hg. 2+ The selectivity. As shown in Table 1, in a single channel (such as ΔA) 530nm Hg 2+ The response ratio to interfering metal ions can reach at least 3.62 times, while in combined channels (such as ΔA) 416nm *ΔA 530nm Under these conditions, the response ratio can reach at least 12.03 times. Based on eight different reading signal modes (single-signal channel and dual-signal combined channel) of Au-Ag-CrNCs, Hg 2+ It can detect quickly (about 2 minutes) and selectively. Figure 3C-3J Due to the effect of Au-Ag-CrNCs on Hg 2+ Au-Ag-CrNCs are most sensitive among all metal ions, therefore their resistance to interference in the presence of other metal ions or anions / reducing agents was also investigated. When Hg... 2+ When coexisting with various metal ions and anions / reducing agents, the color, Tyndall effect, and absorption response of Au-Ag-CrNCs solutions at two wavelengths are compared with those in the presence of only Hg. 2+The results show that when metal ions or anions / reducing agents react with Hg, the reaction is similar (differences are only 0.0003-0.007au). 2+ When coexisting, Au-Ag-CrNCs still exhibit excellent anti-interference ability and do not interfere with the effect of Au-Ag-CrNCs on Hg. 2+ Measurement.

[0048]

[0049] Table 1. Hg in different signal channels (including single-channel and combined-channel) 2+ A comparison of selectivity and detection limit.

[0050] When another analyte (13 anions / reducing agents) is added to Au-Ag-Cr NCs, the effect of Au-Ag-Cr NCs on ClO - The response is most sensitive. In ClO - In the presence of these substances, the color of the Au-Ag-CrNCs solution changes from light brown to light purple. Figure 4A Meanwhile, the characteristic absorption bands of AgNPs and AuNPs decreased significantly. Figure 4B No significant selectivity was observed for other interfering substances. For ClO... - We also selected three discrete channels (ΔA) 416nm ΔA 530nm and ΔA 700nm ). Figure 4C -E shows that Au-Ag-CrNCs exhibit responsiveness to ClO in these three discrete channels. - The absorption response is most pronounced (ΔA) 416nm =0.391au, ΔA 530nm =0.137au, ΔA 700nm =0.89au), these values ​​are at least 7.40, 2.8, and -3.42 times that of other interfering substances, respectively. By combining the absorption changes at two fixed wavelengths, ClO - ΔA 416nm *ΔA 530nm ΔA 416nm *ΔA 700nm and ΔA 530nm *ΔA 700nm The values ​​were 0.0535, 0.0348, and 0.0122 au, respectively, which are at least 38.49, 43.37, and 9.67 times higher than other interfering substances. Figure 4F-4H By summing the absorption changes over different wavelength ranges, ClO - SUMΔA (328-500nm) and SUMΔA (502-700nm)The values ​​were 18.22 and 11.35 au, respectively, which are at least -6.77 and 3.98 times higher than other interfering substances. Figure 4I , Figure 4J The results show that combined channel analysis can improve the detection of ClO₂. - The selectivity and sensitivity. As shown in Table 2, based on the eight different reading signal modes mentioned above, ClO - It can detect quickly (about 2 minutes) and selectively. Figure 4C-4J Furthermore, when ClO - The color, Tyndall effect, and absorption response of Au-Ag-CrNCs solutions at two wavelengths when coexisting with different metal ions and anions / reducing agents are different from those when only ClO is present. - The similarity observed at the time (difference only 0.0001-0.008au) indicates that the presence of metal ions or anions / reducing agents does not interfere with the effect of Au-Ag-CrNCs on ClO. - Measurements showed that Au-Ag-CrNCs still exhibited good anti-interference capabilities.

[0051]

[0052] Table 2. ClO in different signal channels (including single-channel and dual-signal combination channels) - A comparison of selectivity and detection limit.

[0053] Due to Au–Ag–CrNCs' effect on Hg 2+ and ClO - The response of Au–Ag–CrNCs to different concentrations of Hg was more sensitive than that of other detectable substances. We further investigated the effect of Au–Ag–CrNCs on different concentrations of Hg. 2+ and ClO - The colorimetric response in Hg. 2+ When the concentration range is 0.125 to 30 μM, the solution color does not change significantly; however, the characteristic absorption peaks of Ag NPs and Au NPs gradually decrease, while the characteristic peak of Ag NPs shows a significant shift. Figure 5A , Figure 5B With Hg 2+ As the concentration increased to 30 μM, the color of Au–Ag–CrNCs changed from light brown to light purple, and the absorbance decreased significantly. However, starting from 60 μM, the decrease in absorbance became more gradual, reaching its minimum at approximately 450 μM. For a single channel, ΔA 416nm ΔA 530nm and ΔA 700nm It exhibits a positive correlation within a certain concentration range. Figure 5C , 5E And 5G), the absorption changes of Au–Ag–CrNCs and Hg 2+The concentration varied from 0.125 to 90 μM (ΔA). 416nm ) and 90–450 μM (ΔA 416nm ), 0.125~60μM(ΔA) 530nm ) and 60–450 μM (ΔA 530nm ), and 0.125–90 μM (ΔA) 700nm ) and 150–450 μM (ΔA 700nm They exhibit a linear relationship within the range of ). Their calibration equation is y1 = 0.0046x1 + 0.0127(R1). 2 =0.983), y1'=0.000192x1'+0.408 (R1'2=0.989, Figure 5D ); y2 = 0.0018x2 + 0.01087(R2) 2 =0.991) and y2' = 0.000132x2' + 0.12179(R2') 2 =0.982, Figure 5F ); and y3 = 0.00119x3 + 0.00465(R3) 2 =0.988) and y3' = 0.000068x3' + 0.114 (R3'2 = 0.978, Figure 5H According to the 3σ principle, they are related to Hg. 2+ The limits of detection (LOD) were 0.039 μM (ΔA). 416nm ), 0.203 μM (ΔA) 530nm ) and 0.167 μM (ΔA 700nm )

[0054] Furthermore, based on the response to Hg2+, the associated combined channel ΔA 416nm *ΔA 530nm ΔA 416nm *ΔA 700nm ΔA 530nm *ΔA 700nm SUMΔA (328-500nm) and SUMΔA (502-700nm) It exhibits a positive correlation within a certain concentration range. Figure 5I , 5K 5M, 5O, and 5Q). These combined channels are associated with Hg. 2+ In the range of 0.25–90 μM (ΔA) 416nm *ΔA 530nm ) and 90–330 μM (ΔA 416nm *ΔA 530nm ), 0.5~90μM(ΔA) 416nm *ΔA 700nm ) and 90–450 μM (ΔA 416nm ΔA700nm ), 0.125~60μM(ΔA) 530nm *ΔA 700nm ) and 90–450 μM (ΔA 530nm *ΔA 700nm ), 0.125~60μM (SUMΔA) (328-500nm) ) and 60–450 μM (SUMΔA) (328-500nm) ), and 0.125–90 μM (SUMΔA) (502-700nm) ) and 90–450 μM (SUMΔA) (502-700nm) They exhibit a linear relationship. Their calibration equation is as follows: y4 = 0.00056x4 - 0.00017(R4) 2 =0.956), y4'=0.000098x4'+0.0467(R4' 2 =0.997, ΔA 416nm *ΔA 530nm LOD = 0.027nM Figure 5J ), y5=0.00047x5-0.00022(R5) 2 =0.945), y5'=0.000068x5'+0.0418(R5' 2 =0.99, ΔA 416nm *ΔA 700nm LOD = 0.018nM Figure 5L ), y6=0.000106x6-0.0000081(R6 2 =0.980), y6'=0.00003x6'+0.01316(R6' 2 =0.984, ΔA 530nm *ΔA 700nm LOD = 0.183 nM Figure 5N ), y7=0.0358x7+0.703(R7) 2 =0.999), y7'=0.0215x7'+20.929(R7' 2 =0.992, SUMΔA (328-500nm) LOD = 0.646 μM Figure 5P ), y8=0.119x8+0.354(R8) 2 =0.997), y8'=0.00889x8'+10.22(R8' 2 =0.998, SUMΔA (502-700nm) LOD = 2.16 μM Figure 5R In the aforementioned channel, ΔA 416nm *ΔA 700nm and ΔA 416nm*ΔA 530nm The two combined channels exhibited the highest detection sensitivity, with LODs of 0.018 nM and 0.027 nM, respectively, both below the permissible inorganic Hg levels in drinking water. 2+ The highest limit (10 nM). The method used in this study has a relatively comparable linear range, even for Hg. 2+ The detection limit is lower than that reported in other studies. By combining channels, it is possible to detect Hg. 2+ High sensitivity and selective detection.

[0055] Similarly, in ClO - The concentration range is 0.125–30 μM, with ClO - With increasing concentration, the color of the mixed solution did not change significantly. When the concentration reached 60 μM, the solution color changed from light brown to light purple, and then there were no further noticeable color changes. Figure 7A The characteristic absorption peak of Ag NPs (approximately 416 nm) decreases significantly between 0.125 and 60 μM, and disappears completely at 60 μM, without any significant shift in peak position. Meanwhile, the characteristic absorption peak of Au NPs (approximately 530 nm) at ClO... - The absorption gradually decreased within the concentration range of 0.125 to 450 μM, and no significant shift was observed. For the single-channel response, the absorption change of Au-Ag-CrNCs was similar to that of ClO. - The concentration showed a linear relationship, ranging from 0.25 to 90 μM (ΔA). 416nm ) and 90–450 μM (ΔA 416nm ), 1~210μM(ΔA 530nm ), and 0.25–150 μM (ΔA) 700nm Their calibration equation is y1 = 0.00417x1 - 0.00853(R1). 2 =0.994, Figure 6D ), y1'=0.000288x1'+0.3408(R1' 2 =0.977, Figure 6D ); y2 = 0.000814x2

[0056] -0.00062(R2 2 =0.996, Figure 6F ), and y3 = 0.00099x3 - 0.0082(R3) 2 =0.995, Figure 6H Based on the 3σ principle, they are effective against ClO₂. - The detection limit is 0.043 μM (ΔA). 416nm ), 0.449 μM (ΔA) 530nm ) and 0.200 μM (ΔA700 nm).

[0057] Furthermore, based on ClO - The response of the combined channel ΔA 416nm *ΔA 530nm ΔA 416nm *ΔA 700nm ΔA 530nm *ΔA 700nm SUMΔA (328-500nm) and SUMΔA (502-700nm) They exhibit a positive correlation within a certain concentration range. Figure 6I , 6K 6M, 6O, and 6Q). These combined channels are associated with ClO - They exhibit a linear relationship within their respective ranges: 15–210 μM (ΔA) 416nm *ΔA 530nm ), 15~210μM(ΔA 416nm *ΔA 700nm ), 15~330μM (ΔA) 530nm *ΔA 700nm ), 0.25~210μM (SUMΔA) (328-500nm) ) and 0.125–210 μM (SUMΔA) (502-700nm) Their calibration equation is: y4 = 0.00035x4 - 0.0052(R4) 2 =0.983, ΔA 416nm *ΔA 530nm The LOD is 0.043 nM. Figure 6J ), y5=0.00038x5–0.00531(R5 2 =0.981, ΔA 416nm *ΔA 700nm The LOD is 0.026nM. Figure 6L ), y6=0.000099x6–0.00141(R6 2 =0.987, ΔA 530nm *ΔA 700nm The LOD is 0.196 nM. Figure 6N ), y7=0.1064x7–0.0848(R7) 2 =0.995, SUMΔA (328-500nm) The LOD is 2.17 μM. Figure 6P ), y8=0.07046x8–0.2793(R8 2 =0.998, SUMΔA (502-700nm) The LOD is 3.65 μM. Figure 6R In these combined channels, ΔA 416nm *ΔA700nm and ΔA 416nm *ΔA 530nm The combined channel exhibits the highest sensitivity, with LODs of 0.026 nM and 0.043 nM, respectively, both lower than the World Health Organization's (WHO) allowable limit for ClO₂ in drinking water. - The minimum limit (0.2 mg / L, approximately 388.7 nM, calculated as free chlorine) is different from other reported ClO₂ levels. - Compared to other detection methods, our proposed method has a comparable linear range and even a lower detection limit. Results show that it can be achieved through a dual-signal combination channel (ΔA). 416nm *ΔA 700nm and ΔA 416nm *ΔA 530nm Sensitive and selective detection of Hg 2+ and ClO - .

[0058] To study Hg 2+ The effect of transmission electron microscopy (TEM) on the morphology of Au-Ag-CrNCs was characterized. Figure 7A Au-Ag-CrNCs exhibited a non-uniform size distribution, containing both small particles and aggregated large particles. Simultaneously, the particle diameter distribution decreased from 14.15 ± 0.63 nm to 7.74 ± 0.30 nm (R0). 2 =0.997, N=322, Figure 7B This is attributed to Hg 2+ Etching effect on Au / Ag NPs. Furthermore, the addition of Hg... 2+ Afterwards, the edges of CrNBs become rounded, and branching structures are no longer observed. Figure 7A , 7C And 7D). Energy dispersive spectroscopy (EDS) elemental mapping results ( Figure 7E-7M The results indicate that Hg, Au, and Ag in the mixture exhibit strong co-localization, the purple intensity of CrNBs is weakened, while N, O, and S elements are uniformly distributed within the CrNBs range. These results suggest that Hg... 2+ The etching effect on Au / Ag NPs in Au-Ag-CrNCs reduces the Au / Ag NPs ratio, leading to a decrease in absorption intensity and a blue shift in the absorption peak of Ag NPs. Figure 7D We also performed TEM characterization on mixtures of Au-Ag-Cr NCs and ClO-. (The text abruptly ends here, likely due to an incomplete sentence or missing information.) - Afterwards, the number of nanoparticles on CrNBs decreased significantly. Figure 8A The average particle diameter decreased from 14.15±0.63 nm to 8.08±0.24 nm (R²=0.997, N=406, Figure 8BEnergy dispersive spectroscopy (EDS) elemental mapping results further showed that Cl was distributed throughout the Au-Ag-CrNCs region and had strong co-localization with Au, Ag, and Cr; while the distribution changes of other elements were not as pronounced as those after the addition of ClO. - The front is obvious ( Figure 8C-7M These results indicate that exposure to ClO - Subsequently, the etching of Ag atoms from Au-Ag-CrNCs leads to a decrease in Ag content, resulting in a decrease in absorption intensity. Figure 8D ).

[0059] Furthermore, we evaluated the detection of Hg in actual water samples (pool water and tap water) using the prepared Au-Ag-CrNCs. 2+ and ClO - Feasibility (Tables 3-6). Adding Hg to the pool water. 2+ The recoveries ranged from 101.29% to 132.72%, with relative standard deviations (RSDs) between 0.62% and 8.64%. Hg was added to tap water samples. 2+ The recoveries ranged from 94.26% to 121.70%, with RSDs between 1.24% and 8.29% (Hg). 2+ Addition levels 15–90 μM (Tables 3 and 4). At different ClO₂ levels... - In the addition levels (15–210 μM, Tables 5 and 6), ClO was added to the pool water samples. - The recoveries ranged from 100.95% to 117.93%, with RSDs between 0.46% and 3.46% (Note: when ClO was added...). - When the concentration is 0 μM, due to the presence of a large number of impurities in the pool water, in channel SUMΔA (328-500nm) and SUMΔA (502-700nm) The detected concentration was relatively high; while ClO was added to the tap water sample. - The recoveries ranged from 96.11% to 120.00%, with RSDs between 1.68% and 4.69%.

[0060]

[0061] a Not detected.

[0062] Table 3. Detection of Hg2+ in pond water samples from eight different channels.

[0063]

[0064]

[0065] aNot detected.

[0066] Table 4. Hg levels in tap water samples from eight different sources 2+ The detection.

[0067]

[0068] Table 5. Detection of ClO- in pond water samples from eight different channels.

[0069]

[0070] Table 6 shows the ClO content in tap water samples detected under eight different channels. - .

[0071] Recently, molecular logic computing has attracted widespread attention from scientists because it enables information processing at the molecular scale, thus holding great potential in next-generation information technology, medical diagnostics, and molecular science. Since Au-Ag-CrNCs exhibit multi-signal colorimetric responses to a variety of substances, different substances added to Au-Ag-CrNCs (such as Hg) can be used to analyze their colorimetric responses. 2+ ,ClO - Using GSH or H2O2 as inputs and utilizing colorimetric changes (color, absorbance, and their absolute differences) in multiple signal channels as outputs, a series of basic logic gates and advanced cascaded logic circuits can be constructed. Figure 9A (b), (c)). The presence or absence of a substance is defined as logic "1" and logic "0" respectively; the purple color of the solution, absorbance, or their absolute difference (A2) 64nm >1.10, 1.10 or 1.16, |ΔA 264nm |> 0.10, 0.03, or 0.10, A 332nm >0.77, 0.82, or 0.85, |ΔA 332nm |>0.03, 0.04 or 0.06, A 416nm >0.90, 0.92, or 0.80, |ΔA 416nm |> 0.20, 0.17, or 0.10, A 530nm >0.90, 0.94, or 0.90, |ΔA 530nm Values ​​of 0.02, 0.03, or 0.06 are defined as "1", otherwise as "0". It is important to note that the absorbance variation at 264 nm is attributed to the signal response of CrNBs in Au-Ag-CrNCs to the additive. The selection of absorbance data at 332 nm and different data processing methods for each channel aims to increase the number of output channels, enabling more types of logical calculations and providing greater storage capacity for subsequent information encoding.

[0072] When Hg2+ When GSH is introduced into Au-Ag-Cr NCs and different data processing methods are used, four different logic gates (YES, OR, INHIBIT, IMPLY) can be constructed based on the output of the nine signal channels. Figure 9B Au-Ag-CrNCs (corresponding to input 0,0) presents a light brown solution with two strong absorption bands at 416 nm and 530 nm. The presence of GSH alone (corresponding to input 0,1) does not significantly change the solution color, but leads to increased absorbance at 264 nm and 332 nm. Conversely, the presence of Hg alone... 2+ The presence of (corresponding to input 1,0) causes the solution to turn purple, while the absorbance decreases at 264, 416, and 530 nm, and slightly increases at 332 nm. When GSH and Hg... 2+ When Au-Ag-CrNCs were added simultaneously (corresponding to input 1,1), the solution color did not change significantly, and the absorbance only increased at 264 and 332 nm. In other words, when only GSH or Hg is present... 2+ At that time, they react with CrNBs in Au-Ag-CrNCs, causing changes in the absorbance at 264 and 332 nm, while Hg 2+ This also leads to a significant reduction in the characteristic absorption peaks of Au-Ag-CrNCs; however, their combination does not change the color of the solution or the characteristic absorption peaks of Au-Ag-CrNCs. Analyzing the above input-output relationship from a logical calculation perspective, for |ΔA 264nm |、A 332nm and |ΔA 332nm The output of |GSH, the presence of which (logical input 1) causes |ΔA 264nm |、A 332nm and |ΔA 332nm |A significant increase, corresponding to the YES gate (Boolean algebra B). For |ΔA 530nm The output of | whether it's GSH or Hg 2+ The existence of (logical input 1) makes |ΔA 530nm | A threshold exceeding 0.02 corresponds to the OR gate (Boolean algebra A+B). For color output and |ΔA 416nm In the case of |, when only Hg2+ is present, the solution only turns purple, and the absolute difference in absorbance is significantly greater than the other three combinations (logic output 1), corresponding to the INHIBIT gate (Boolean algebra AB'). Considering A 264nm A 416nm and A 530nm When outputting, only Hg exists. 2+ This will cause A 264nm A 416nm and A 530nmIf the value is below the corresponding threshold (output 0), otherwise output 1, corresponding to the IMPLY gate function (Boolean algebra A'+B).

[0073] When ClO - When Au-Ag-CrNCs are introduced with H2O2 as two inputs, five types of logic gates (OR, NAND, INHIBIT, IMPLY, XOR) can be constructed based on Au-Ag-CrNCs. Figure 9C The presence of H₂O₂ alone turns the solution purple, and the absorption peak at 416 nm decreases, which can be attributed to the strong oxidizing property of H₂O₂. Similarly, the presence of ClO⁻ alone also turns the solution purple, increases the absorbance at 264 nm and 332 nm, and eliminates the absorption peak at 416 nm. When ClO⁻ and H₂O₂ coexist, the absorbance at 264 nm and 332 nm decreases, and the absorption at 416 nm decreases but does not disappear, possibly because ClO⁻ and H₂O₂ react to form Cl₂. - H2O and O2. Analyzing the relationship between the above inputs and outputs from a logical calculation perspective, for color output, when ClO is present... - The solution turns purple when H2O2 is present (logic output 1), corresponding to the OR gate function (Boolean algebra A+B). When ClO2 is present... - When coexisting with H2O2, the output is A. 264nm and A 530nm A threshold less than 1.10 or 0.84 corresponds to the NAND gate function (Boolean algebra A'+B'). Regarding |ΔA 264nm The output of |ΔA of the solution only when H2O2 is present alone. 264nm A threshold greater than 0.03 (logic output 1) corresponds to the INHIBIT gate function (Boolean algebra A'B); while for A... 332nm and |ΔA 332nm The output of | only when ClO - When present alone, the output exceeds the threshold of 0.82 or 0.04 (logic output 1), corresponding to the INHIBIT gate function (Boolean algebra AB'). For the output of A416 nm, when only ClO is present... - When the output is less than the threshold of 0.92 (logic output 0), it corresponds to the IMPLY gate function (Boolean algebra A'+B). Furthermore, based on |ΔA 416nm |and|ΔA 530nm The output of | can be used to construct an XOR gate (Boolean algebra A'B+AB'). Interestingly, this can be achieved using ClO. - Using H2O2 as two inputs, construct two more advanced combinational logic circuit half-subtractors, with |ΔA 264nm |and|ΔA 416nm |(or|ΔA)530nm |) as two outputs ( Figure 9C (The light green markers in the truth table) correspond to borrowing and difference, respectively (see...) Figure 9A (c), Green Logic Symbol). This semi-subtractor algorithm provides a new approach to typical molecule-based arithmetic operations and drives the development of advanced molecular logic devices.

[0074] In addition, using Hg 2+ and ClO - As two inputs, four different types of logic gates (OR, YES, AND, NOT) can also be created. Figure 9D For color output and |ΔA 416nm |, if Hg exists 2+ or ClO - (Logical input 1) will cause the solution to turn purple or |ΔA 416nm | A threshold exceeding 0.10 (logic output 1) corresponds to the OR gate function (Boolean algebra A+B). For output A 264nm A 332nm and |ΔA 332nm |, if ClO is present - If the logical input is 1, the output will be greater than the threshold of 1.16, 0.85, or 0.06 (logical output 1), corresponding to the YES gate function (Boolean algebra B); while for |ΔA 530nm The output of | if Hg exists 2+ If the logical input is 1, the output will be greater than the threshold of 0.06 (logical output 1), which also corresponds to the YES gate function (Boolean algebra A). |ΔA 263nm | Output only in Hg 2+ and ClO - When both exist simultaneously, a threshold exceeding 0.10 (logic output 1) is encountered, corresponding to the AND gate function (Boolean algebra AB). For A 416nm and A 530nm The output of only when Hg 2+ The output will only exceed the threshold of 0.80 or 0.90 (logic output 1) when a logical input is missing (0), corresponding to the NOT gate function (Boolean algebra A'). Furthermore, by combining multiple outputs (A'... 264nm (or A) 332nm , or |ΔA 332nm |) and |ΔA 530nm |, Figure 9D (The light blue markers in the truth table) can be used to construct important pass-through gates. These gates pass the input state to the output without any logical change (0 remains 0, 1 remains 1; input A = output |ΔA) 530nm |, Input B = Output A 264nm (or A)332nm , or |ΔA 332nm In a cascaded logic gate system, the output of one gate is converted into the input of another. This cascading is essential for performing complex computational operations using molecular logic. In Au-Ag-CrNCs systems, these two gates form a logically invertible system, where each input combination produces a unique output. Figure 9D (The truth table is marked in light blue). Therefore, only the single output (A) is used. 264nm A 332nm 、|ΔA 332nm |or|ΔA 530nm This will lead to information loss. Reversible logic solves this problem by ensuring that each input vector corresponds to a unique output vector, which is becoming increasingly important in electronic computers and molecular logic. Therefore, the multi-channel and multi-target sensing capabilities of Au-Ag-Cr NCs can facilitate various batch and parallel multifunctional molecular logic computations.

[0075] In recent years, molecular or nanoscale systems capable of performing information encoding, encryption, and concealment have attracted the attention of scientists such as chemists, materials scientists, and information scientists due to their unique information representation and protection paradigms. Figure 10A This demonstrates the classic model of information encryption (cryptography) and concealment (steganography). Cryptography is the study of compiling secret communications into incomprehensible gibberish, which is then decrypted to retrieve the communication information. Figure 10A (a)). Steganography, on the other hand, hides specific information within a normal medium to conceal the existence of special information. Figure 10A (b) Molecular or nanoscale systems can provide new encryption mechanisms and materials for information protection. Combining cryptography and steganography in molecular or nanoscale systems can achieve a higher level of information security.

[0076] In this study, the selective response of the Au-Ag-Cr NCs nanosystem can be encoded, encrypted, and concealed using steganographic cryptography. Figure 10B By adding 19 metal ions and 13 anions or reducing agents as steganalytic keys, Au-Ag-Cr NCs can be used as steganalytic targets to produce multi-signal selective responses (such as color and absorption changes) as outputs. Figure 10B (a)). Based on different threshold settings (ΔA) 416nm For "0.018" or "0.012", ΔA 530nm and ΔA 700nm For example, the selective response of Au-Ag-Cr NCs across eight channels can be converted into a total of 16 lines of 19-bit and 13-bit binary strings. This corresponds to the decoding process, i.e., obtaining hidden information through steganalysis. Figure 10B (a)→(b)). Since the hidden information composed of these binary strings is encrypted, the correct cryptographic key must be used for the next step of decryption. Therefore, by truncating these sixteen lines of 19-bit and 13-bit binary strings into shorter binary strings (moving sequentially from the first position), we can obtain 14 six-bit and 8 six-bit binary strings, or 13 seven-bit and 7 seven-bit binary strings, which serve as the basic information encoding units. Figure 10B (c)). These 6-bit and 7-bit strings can be used to encode corresponding numbers of characters (14 and 8, or 13 and 7). Using simple transposition ciphers or multi-letter ciphers, permutations and combinations of 6-bit binary strings (2...) can be used. 6 =64) or 7-bit binary string (2 7 =128) encodes 27, 28, 53, 54, or 55 common characters in a many-to-one manner. Using the correct key, the hidden and encrypted information in Au-Ag-CrNCs can be decrypted to obtain the following plaintext ( Figure 10B (d) "The only way to do great work is to love what you do. If you haven't found it yet, keep looking. Don't stop until you find something you love. — Steve Jobs." (From Steve Jobs' commencement address at Stanford University on June 12, 2005, as shown in Example 1) and "He was an old man who was fishing alone in a small boat in the Gulf Stream and had not caught a fish for 84 days. — Ernest Hemingway, The Old Man and the Sea." (The opening of the famous novel The Old Man and the Sea, setting the scene and introducing the protagonist, as shown in Example 2).

[0077] Furthermore, the logical input-output relationship of Au-Ag-Cr NCs (Figure 9) can also be used for encoding, encryption, and concealing information (molecular cryptography steganography). Figure 10C When three substances are added as steganographic keys, such as Hg... 2+ and GSH, ClO - and H2O2, or Hg 2+ and ClO - Au-Ag-Cr NCs, as stegtext objects, generate multiple signal responses (e.g., color, A). 264nm 、|ΔA 264nm |、A 332nm 、|ΔA 332nm |、A 416nm 、|ΔA 416nm |、A 530nm and |ΔA 530nm |, Figure 10C (a)). By arranging and combining three sets of truth tables (2 inputs + 9 channel outputs), Figure 10C(b) generates a total of 12 lines of 11-bit binary strings. The above process is equivalent to steganalysis (i.e., obtaining hidden information by converting the input and output to binary). Figure 10C (a), (b)). Figure 10C (c) illustrates the specific process of decrypting these 0 / 1 binary strings into the corresponding understandable plaintext. To encode more information, we... Figure 10C (b) The obtained 12-line 11-bit binary string was segmented and combined. For example, by combining the two input 12-line 0 / 1 strings (represented as C0) with color, A 264nm 、|ΔA 264nm | The three outputs consist of 12 lines of 0 / 1 strings (represented as C1) and A 332nm 、|ΔA 332nm |、A 416nm Combining the three output lines of 12 0 / 1 strings (denoted as C2), we obtain a 12-line 8-bit binary string (denoted as C0+C1+C2). Similarly, we can obtain two other combinations: 8-bit C0+C2+C3 and 8-bit C0+C3+C1. These 12 lines of 8-bit binary strings can be used to encode specific characters (...). Figure 10C (c)). Using a simple multi-letter cipher, 65 common characters can be encoded in a many-to-one manner using 8-bit permutations (2^8 = 256). Simultaneously, based on the 8-bit cipher key, information in 12 lines of 8-bit binary strings can be decrypted to obtain the following plaintext fragments: “Live”, “to d”, “ie t” (lines 1-4), “as”, “ere”, “omor” (lines 5-8), “if y”, “ouw”, “row” (lines 9-12). By combining these individual pieces of information and interpreting their meaning, the corresponding plaintext message “Live as if you were to die tomorrow.” can be obtained. Therefore, the above results demonstrate that Au-Ag-Cr NCs not only provide unique nanocarriers / coatings with their inherent multi-signal selective response and input-output logic, but also offer a molecular paradigm for information encoding, encryption, and concealment.

[0078] In summary, the Au-Ag-CrNCs synthesized using a simple and efficient method not only enable multimodal and multianalyte colorimetric sensing but also play a significant role in advanced MIT (including molecular advanced arithmetic logic and reversible logic, as well as information encryption and concealment). Au-Cr nanoseeds are generated through a pre-reaction process, and these nanoseeds are then combined with Ag... +Au-Ag-CrNCs coated with SDBS were successfully prepared by mixing stabilizer SDBS and reducing agent AA. The morphological characteristics of Au-Ag-CrNCs consisted of Au / Ag nanoparticles (average diameter 14.15 ± 0.63 nm) attached to branched chromium nanoribbons, with an average branch diameter of 56.93 ± 2.77 nm. By analyzing multi-signal changes in color, Tyndall effect, and absorption, Au-Ag-CrNCs were able to selectively and quantitatively detect two analytes (Hg) 2+ and ClO - Furthermore, the combination of signal channels significantly improves selectivity and sensitivity. 2+ and ClO - The addition of [unclear] triggered the etching of Au / Ag nanoparticles in the nanocomposite material, resulting in changes in color and absorption. Furthermore, by using different substances as inputs and the signal changes in the generated solution as outputs, basic logic gates and advanced logic circuits (half-subtractors and transmission gates) can be constructed. Simultaneously, by performing binary conversion on the multi-signal responses, molecular information encoding, encryption, and steganography based on the logical relationships and selective responses of Au-Ag-Cr NCs can be achieved. Compared with previous studies, this research demonstrates the following advantages in the preparation and application of Au-Ag-Cr NCs: (1) updating the preparation mode and comprehensive application scenarios of multi-component materials to achieve optimized and customized material properties; (2) developing new signal channel combination methods to improve sensing selectivity and sensitivity; (3) utilizing multi-channel responses to expand the scale, parallelism, and paradigm of molecular logic computation; and (4) enriching the dimension and universality of molecular information to enhance the information density and anti-interference capabilities of information security. In the future, the electrochemical, catalytic, and biological applications of Au-Ag-Cr NCs deserve further attention and exploration. Inspired by this research, the preparation and application of multimetal / multielement nanomaterials will drive materials science towards higher levels of integration and functionality. Furthermore, the fusion of molecular sensing and information technology will unleash even greater vitality, pushing the boundaries of next-generation information technology and molecular science.

[0079] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A method for preparing a gold-silver-chromium nanocomposite material, characterized in that, It was prepared at room temperature using Au-Cr nanoseed method, ascorbic acid reducing agent and sodium dodecylbenzenesulfonate stabilizer.

2. The preparation method according to claim 1, characterized in that, Cr was mixed sequentially in an ice bath 6+ Au 3+ Au-Cr nanoseeds were prepared by reacting with NaBH4 for 15 minutes, then allowed to stand at room temperature for 15 minutes, and then centrifuged and resuspended. The preparation steps for ternary materials based on Au-Ag nanoseeds and Ag-Cr nanoseeds are the same. Next, 250 μL of Au-Cr nanoseeds were mixed with 175 μL of 10 mM AgNO3 and 175 μL of 10 mM ascorbic acid at a concentration ratio of Au ion to Cr ion of 1:

2. 400 μL of 10 mM SDBS was added, and the total liquid volume was adjusted to 1000 μL. After reacting at room temperature for 70 minutes, the mixture was centrifuged and resuspended twice.

3. A gold-silver-chromium nanocomposite material prepared as claimed in claim 1 or 2.

4. The gold-silver-chromium nanocomposite material according to any one of claims 1-3 in Hg 2+ Applications in detection.

5. The application of the gold-silver-chromium nanocomposite material according to any one of claims 1-3 in the detection of hypochlorite.

6. The application of the gold-silver-chromium nanocomposite material according to any one of claims 1-3 in information encryption.

Images