Miniature optical anti-counterfeiting tag based on single-molecule quantum coherence and reading system and preparation method thereof

Abstract

The application provides a micro optical anti-counterfeiting label based on single-molecule quantum coherence and a reading system and a preparation method thereof, and belongs to the technical field of micro optical anti-counterfeiting labels; solves the problems of high preparation cost, easy damage and easy environmental interference of traditional micro optical anti-counterfeiting label technology; uses inkjet printing technology to construct anti-counterfeiting information through spatial distribution of single molecules; uses inherent coherence characteristics of single molecules as an anti-counterfeiting information carrier; detects single-molecule coherence dynamics evolution through femtosecond double-pulse pumping detection technology; realizes frequency domain imaging by extracting modulation intensity through DFT transformation; and adds quantum dots on single molecules as interference signals to improve the noise resistance and information hiding capacity of the anti-counterfeiting label.

Description

Technical Field

[0001] This invention provides a micro-optical anti-counterfeiting label based on single-molecule quantum coherence, its reading system, and its preparation method, belonging to the field of micro-optical anti-counterfeiting label technology. Background Technology

[0002] With the continuous development of big data and the deepening research into microscopic dynamics, an increasing number of microelectronic components and biometric technologies are being developed. However, counterfeit and substandard products have always been a pest affecting market order, disrupting the economy, and threatening human health. Anti-counterfeiting technology is crucial for ensuring product safety and traceability. Among numerous anti-counterfeiting technologies, optical labels have attracted significant attention due to their complex material composition and optical properties. This makes optical anti-counterfeiting labels difficult to copy and reproduce, thus preventing counterfeiting and tampering. This technology has wide applications in various fields, including protecting high-value goods and improving the safety of pharmaceuticals and food. Furthermore, it has promoted advancements in related fields such as display technology and optical imaging.

[0003] Among the various optical anti-counterfeiting technologies currently under research, fluorescent labels and photochromic labels have emerged as particularly promising candidates. However, the optical materials used in these methods are expensive to prepare, susceptible to physical damage, and exhibit broad-spectrum and environmental sensitivity. These factors collectively make it difficult to ensure the fidelity and secure differentiation of the generated signals. Furthermore, the presence of external background information can easily obscure the encoded signals, posing challenges to the preparation, storage, and use of anti-counterfeiting labels. Summary of the Invention

[0004] To address the problems of high manufacturing cost, susceptibility to damage, and susceptibility to environmental interference in traditional micro-optical anti-counterfeiting label technology, this invention proposes a micro-optical anti-counterfeiting label based on single-molecule quantum coherence, its reading system, and its manufacturing method.

[0005] The technical solution adopted in this invention is as follows: a micro-optical anti-counterfeiting label based on monomolecular quantum coherence, comprising a glass slide, wherein a monomolecular layer, an isolation layer and an interference layer are sequentially disposed on the glass slide, wherein a monomolecular layer is distributed with a single dye molecule pattern carrying anti-counterfeiting label information, and the interference layer is distributed with quantum dots as interference information.

[0006] Furthermore, the anti-counterfeiting label information in the monolayer is obtained by inkjet printing technology.

[0007] Furthermore, the monolayer is selected from a single dye molecule of Cy5, SR, or Terrylene, with a molecular density of 1-30 molecules / μm. 2 .

[0008] Furthermore, the isolation layer is a sandwich isolation layer, comprising a PMMA film, a glycerol-based anti-quenching sealing agent, and a PMMA film.

[0009] Furthermore, the thickness of each layer of the sandwich isolation layer is 1-20 nm.

[0010] Furthermore, the quantum dots are selected from group II-VI quantum dots, and the density of quantum dots is 1-30 per μm. 2 .

[0011] A method for preparing a micro-optical anti-counterfeiting tag based on single-molecule quantum coherence includes the following steps:

[0012] S1: Preparation of unimolecular solutions and quantum dot solutions;

[0013] S2: Printing a monolayer using inkjet printing technology;

[0014] S3: After air drying, an isolation layer and an interference layer are sequentially prepared on a monolayer using a spin coating method.

[0015] Furthermore, the single-molecule solution and quantum dot solution are prepared by a dilution method, and the density of the single molecules and quantum dots is determined by wide-field electron multiplication EMCCD imaging to determine whether the density meets the requirements.

[0016] A system for reading anti-counterfeiting tags prepared by a method for fabricating micro-optical anti-counterfeiting tags based on single-molecule quantum coherence includes an optical path section and an electrical control section. The optical path section employs a femtosecond dual-pulse pump-probe module. The electrical control section includes a time delay control module, a phase modulation module, and a PC terminal. The femtosecond dual-pulse pump-probe module includes a femtosecond laser. After polarization purification by a polarizing beam splitter, the femtosecond laser is split into two paths by a first reflecting mirror and a first unpolarizing beam splitter. One path is emitted to a fourth reflecting mirror after passing through an electro-optic modulation crystal. The phase modulation module controls the voltage applied to the EOM (Electro-Optical Array). The frequency is transmitted via another path to a third reflector fixed on the stepper motor. The two reflected signals are combined by the first unpolarized beam splitter, then pass through the first filter, the first beam expander, and the second unpolarized beam splitter before being focused onto the surface of the anti-counterfeiting label by the objective lens. The fluorescence signal of the molecules on the anti-counterfeiting label is collected by the objective lens, then passes through the second unpolarized beam splitter, the second filter, the second beam expander, and the lens before being focused onto the EMCCD optical receiving surface and transmitted to the PC. The time delay control module outputs voltage information to adjust the moving speed of the stepper motor, thereby adjusting the position of the third reflector to ensure that the Michelson interference optical path is at the 0-delay position.

[0017] Furthermore, the PC performs a discrete Fourier transform on the photon arrival time sequence of each pixel; and redraws the frequency domain image using the modulation intensity at the modulation frequency as a parameter to complete the reading of the anti-counterfeiting label.

[0018] The advantages of this invention compared to existing technologies are as follows: The micro-optical anti-counterfeiting label based on single-molecule quantum coherence provided by this invention enables the editing and reading of anti-counterfeiting labels at the single-molecule level, effectively improving product security. Specifically, the single-molecule anti-counterfeiting label is edited using inkjet printing technology; quantum dots are added to the single-molecule label as interference signals using spin coating; the influence of the quantum dot preparation process on the single-molecule label is avoided by inserting a PMMA film and a glycerol-based fluorescence quenching inhibitor between layers; a single-molecule coherent superposition state is prepared using femtosecond dual pulses with adjustable delay phase; and the encoded information is read through quantum coherent imaging modulation and demodulation. This invention utilizes the inherent coherence characteristics of single molecules to design optical anti-counterfeiting labels, which can be widely applied in fields such as biology, medicine, and food safety. Attached Figure Description

[0019] The present invention will be further described below with reference to the accompanying drawings:

[0020] Figure 1 This is a structural diagram of the anti-counterfeiting label prepared in this embodiment;

[0021] Figure 2 This is a structural diagram of the reading system in this embodiment;

[0022] Figure 3 The result of numerical simulation of writing and reading anti-counterfeiting labels is shown in the figure.

[0023] Figure 4 The results of the optical anti-counterfeiting experiment conducted to verify the effectiveness of the anti-counterfeiting label in this embodiment are shown in the figure.

[0024] In the diagram: 101 is a polarizing beam splitter, 1021 is a first reflecting mirror, 1022 is a second reflecting mirror, 1023 is a third reflecting mirror, 1024 is a fourth reflecting mirror, 1031 is a first unpolarizing beam splitter, 1032 is a second unpolarizing beam splitter, 104 is a signal generator, 105 is a high-voltage amplifier, 1061 is a first filter, 1062 is a second filter, 1071 is a first beam expander, 1072 is a second beam expander, 108 is an objective lens, 109 is a lens, and 110 is a stepper motor. Detailed Implementation

[0025] like Figures 1 to 4As shown, this invention provides a micro-optical anti-counterfeiting label based on single-molecule quantum coherence. From bottom to top, the label consists of a glass slide, a monolayer, a sandwich isolation layer, and an interference layer. The monolayer is prepared using inkjet printing technology, and the sandwich isolation layer is prepared using spin coating. The three layers are, in order, PMMA / glycerol-based mounting medium / PMMA, and the topmost interference layer consists of quantum dots prepared by spin coating. This anti-counterfeiting label utilizes the single-molecule quantum coherence properties to carry label information. Through sample preparation, the information carried by the single molecule is hidden beneath the interference information, and the single-molecule coherent modulation signal is read using femtosecond dual-pulse pump-probe technology.

[0026] The optional monomolecules for the monolayer include dye molecules such as Cy5, SR, and Terrylene.

[0027] The sandwich isolation layer consists of a PMMA film, a glycerol-based anti-quenching sealing agent, and another PMMA film, with the thickness of each film controlled between 1-20 nm. All layers are prepared by spin coating. The first PMMA film is used to prevent the monolayer from being dispersed by the glycerol-based anti-quenching sealing agent, which protects the monomolecules from external factors such as environment and light, thereby reducing molecular quenching. The second PMMA film is used to prevent the quantum dot solvent from reacting with the glycerol-based anti-quenching sealing agent, which would affect the anti-quenching effect.

[0028] The optional quantum dots for the interference layer include group II-VI quantum dots, such as CdSe, CdTe, and ZnS.

[0029] This invention also proposes a method for preparing a micro-optical anti-counterfeiting label based on single-molecule quantum coherence, which mainly includes the following steps:

[0030] S1: Preparation of unimolecular solutions and quantum dot solutions;

[0031] S2: Printing a monolayer using inkjet printing technology;

[0032] S3: After air drying, a sandwich isolation layer and an interference layer are sequentially prepared on a monolayer using a spin coating method.

[0033] The monomolecular solution and quantum dot solution were prepared by dilution.

[0034] The specific single-molecule solution is obtained by dissolving dye molecules in dimethyl sulfoxide (DMSO) solution and continuously diluting it to a suitable concentration by adding water. The diluted single-molecule solution is then drop-coated onto a confocal glass slide, allowed to air dry, and then assessed using a wide-field electron multiplication EMCCD imager. The appropriate concentration is determined by ensuring that molecules are individually distributed and that the molecular density is 1-30 molecules / μm. 2 .

[0035] The quantum dot solution is obtained by dissolving quantum dots in dimethyl sulfoxide (DMSO) solution and continuously diluting to a suitable concentration using a water addition method. The concentration distribution is determined using wide-field EMCCD imaging, and interference information is prepared on a sandwich isolation layer using a spin-coating method, requiring a quantum dot density of 1-30 particles / μm after spin-coating. 2 .

[0036] A monolayer was printed on a confocal glass slide using an inkjet printer, with a printing resolution of ≤20μm.

[0037] In anti-counterfeiting label applications, femtosecond dual-pulse pump detection technology can be used to acquire wide-field images of the anti-counterfeiting label. DFT transform is then used to process the photon arrival sequence of each pixel and extract the modulation intensity. The modulation intensity of each pixel is used to draw the actual label information. Therefore, this invention also proposes a reading system for miniature optical anti-counterfeiting labels based on single-molecule quantum coherence, including an optical path section and an electrical control section. The optical path section achieves wide-field imaging of the anti-counterfeiting label through a femtosecond dual-pulse pump detection module. The electrical control section includes a time delay control module, a phase modulation module, and a PC terminal.

[0038] The structure of the femtosecond dual-pulse pump detection module is as follows: Figure 2 Within the rectangular frame, the femtosecond laser beam, after polarization purification by polarizing beam splitter 101, is split into two paths by first reflecting mirror 1021 and first unpolarizing beam splitter 1031. One path passes through an EOM (Electronic Oscillator) and is emitted to a fourth reflecting mirror 1024, where the voltage and frequency applied to the EOM are controlled by a phase adjustment module. The other path is sent to a third reflecting mirror 1023 fixed to a stepper motor 110. The two reflected signals are combined by the first unpolarizing beam splitter 1031 and then converged onto the sample surface by objective lens 108 after passing through components such as first filter 1061 and first beam expander 1071. The fluorescence signal of the molecules is collected by objective lens 108, then converged to the EMCCD optical receiving surface by second filter 1062, second beam expander 1072, and lens 109 before being transmitted to the PC.

[0039] The time delay control module outputs voltage information to adjust the position of the third reflector 1023 on the stepper motor 110, ensuring that the Michelson interference optical path is at the 0-delay position. The phase adjustment module, consisting of a signal generator 104 and a high-voltage amplifier 105, controls the voltage signal applied to the EOM, thereby adjusting the phase of the EOM output signal. The PC terminal includes a data acquisition module and a data processing module, with the data acquisition module consisting of LabVIEW program and Andor spectrometer software.

[0040] The present invention will be further described below with reference to the embodiments shown in the accompanying drawings.

[0041] refer to Figure 1-3This embodiment provides a micro-optical anti-counterfeiting label based on single-molecule quantum coherence, and the steps for its preparation and anti-counterfeiting information reading are as follows:

[0042] Step 1: Preparation of micro-monomer anti-counterfeiting tags;

[0043] Step 1.1: Prepare SR single-molecule solution and CdTeSe / ZnS QDs@800nm ​​(800QDs) solution by solution method;

[0044] Step 1.2: Prepare an SR monomolecular tag pattern in the shape of "H" on a confocal glass slide using inkjet printing technology;

[0045] Step 1.3: Prepare a sandwich isolation layer by spin coating, with a PMMA concentration of 2% and spin coating parameters of 3000 rpm for 30 s. Dry at room temperature for 10 minutes, then bake at 80°C for 30 minutes. A glycerol-based anti-quenching sealing agent is drop-coated onto the PMMA film, and then extruded by adding a cover glass slide on top. After 2 hours, remove the cover glass slide, allow to stand in a drying oven for 24 hours, and then spin-coat the next PMMA film using the same method.

[0046] Step 1.4: Prepare interference information on the sample above by spin coating. In this embodiment, 800 QDs is selected as the interference layer. The spin coating parameters are: ① 500 rpm, 5s; ② 1500 rpm, 10s; ③ 3000 rpm, 30s.

[0047] Step 2: Acquire wide-field imaging of single-molecule anti-counterfeiting labels using a femtosecond dual-pulse pump detection system;

[0048] Step 2.1: The sawtooth wave electrical signal applied to the EOM is controlled by the signal generator 104 and the high voltage amplifier 105 to make the output signal of the EOM positive.

[0049] Step 2.2: After the femtosecond laser is purified by polarization beam splitter 101, it is split into two paths by first reflecting mirror 1021 and first unpolarized beam splitter 1031. One path is emitted to fourth reflecting mirror 1024 after passing through EOM, and the other path is sent to third reflecting mirror 1023 fixed on stepper motor 110. The two reflected signals reflected by third reflecting mirror 1023 and fourth reflecting mirror 1024 are combined by first unpolarized beam splitter 1031 and then reflected by second reflecting mirror 1022. The reflected signals then pass through first filter 1061, first beam expander 1071, second unpolarized beam splitter 1032, and are converged on the sample surface by objective lens 108.

[0050] Step 2.3: The fluorescence signal of the molecule is collected by objective lens 108 and then converged to the EMCCD optical receiving surface by second non-polarizing beam splitter 1032, second filter 1062, second beam expander 1071 and lens 109 and transmitted to PC.

[0051] Step 3: Read the anti-counterfeiting label information;

[0052] Step 3.1: Perform Discrete Fourier Transform (DFT) on the photon arrival time sequence of each pixel on the PC.

[0053] Step 3.2: Redraw the frequency domain image using the modulation intensity at the modulation frequency as a parameter to complete the reading of the anti-counterfeiting label.

[0054] The effectiveness of this invention will be verified through experiments below:

[0055] Figure 1 The structure diagram of the designed anti-counterfeiting label is shown below. From bottom to top, it consists of a glass slide, an SR monomolecular label, a sandwich isolation layer, and interference information. The SR monomolecular layer is prepared by inkjet printing technology, the sandwich isolation layer is prepared by spin coating, and the three materials are PMMA / glycerol-based sealing material / PMMA. The top layer of interference information is CdTeSe / ZnSQDs@800nm, 800QDs prepared by spin coating.

[0056] Figure 2 For the reading system designed for the experiment, the output signal of the signal generator 104 in this embodiment is a sawtooth wave with a voltage of 136V and a frequency of 5Hz.

[0057] Figure 3 To simulate the results of writing and reading the above anti-counterfeiting labels using numerical simulation. Figure 3 (a), (b), and (c) correspond to samples with only SR molecules, samples with SR molecules and 800 QDs, and single-molecule quantum coherent signals extracted using discrete Fourier transform, respectively. Figure 3 In (a), a region of encoded characters ("pseudo") is selected in the image, and 50 coordinate points are randomly selected from this region. Using these coordinate points as centers, a circular region is selected to represent a single molecule, with a radius of 3 or 4 pixels. Based on the original encoded data, interference information is loaded onto the entire selected region, and the above simulation process is performed on 300 randomly selected coordinate points. It should be noted that these photons are not frequency modulated (800 QDs), such as... Figure 3 As shown in (b). This invention is... Figure 3(a) Within the circular region, a photon response time axis is established for each pixel during the EMCCD exposure time, where the probability of detecting photons at different times follows a certain modulation frequency. Photon counting is performed on each time axis, and the count value is used as the light intensity value of the corresponding pixel to obtain the original encoded data. Then, a DFT transform is performed on each time axis to calculate the modulation factor, which is then used as the value of the corresponding pixel to obtain a frequency domain image of the encoded region that retains only the modulation information, such as... Figure 3 As shown in (c).

[0058] Figure 4 This is a demonstration of a miniature optical anti-counterfeiting experiment based on single-molecule quantum coherence. Figure 4 (a) is a wide-field fluorescence image of a single-molecule tag "H" prepared solely by inkjet printing. Figure 4 (b) Wide-field imaging of the sample after preparing a sandwich isolation layer on top of the single-molecule tag "H" and 800 QDs shows that the tag "H" is hidden in the fluorescence imaging and cannot be read by conventional means. Figure 4 (c) is Figure 4 (b) Frequency domain imaging of the sample shows that the quantum dot interference signal disappears because the complex dynamic process inside the quantum dot overwhelms its quantum coherence information, and the single-molecule tag "H" is successfully read with an accuracy of up to 98%. The experimental results are highly consistent with the simulation results, verifying the correctness of the simulation process and the good concealment and fidelity of the anti-counterfeiting tag proposed in this invention.

[0059] This invention utilizes inkjet printing technology to construct anti-counterfeiting information through the spatial distribution of single molecules; it uses the inherent coherence properties of single molecules as the carrier of anti-counterfeiting information; it uses femtosecond dual-pulse technology to detect the coherent dynamic evolution of single molecules; it uses DFT transform to extract modulation intensity to achieve frequency domain imaging; and it enhances the noise resistance and information hiding ability of anti-counterfeiting labels by adding quantum dots to single molecules as interference signals.

[0060] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A micro-optical anti-counterfeiting label based on single-molecule quantum coherence, comprising a glass slide, characterized in that: The glass slide is sequentially provided with a monolayer, an isolation layer and an interference layer. The monolayer is distributed with a single dye molecule pattern carrying anti-counterfeiting label information, and the interference layer is distributed with quantum dots as interference information. The isolation layer is a sandwich isolation layer, comprising a PMMA film, a glycerol-based anti-quenching sealing agent, and a PMMA film; The molecular density of the monolayer is 1-30 molecules / μm. 2 The density of the quantum dots is 1-30 per μm. 2 .

2. The micro-optical anti-counterfeiting label based on single-molecule quantum coherence according to claim 1, characterized in that: The anti-counterfeiting label information in the monolayer is obtained by inkjet printing technology.

3. A micro-optical anti-counterfeiting label based on single-molecule quantum coherence according to claim 2, characterized in that: The monolayer is selected from a single dye molecule of Cy5, SR or Terrylene.

4. A micro-optical anti-counterfeiting label based on single-molecule quantum coherence according to claim 1, characterized in that: Each layer of the sandwich isolation layer has a thickness of 1-20 nm.

5. A micro-optical anti-counterfeiting label based on single-molecule quantum coherence according to claim 1, characterized in that: The quantum dots used are group II-VI quantum dots.

6. A method for preparing a micro-optical anti-counterfeiting label based on single-molecule quantum coherence as described in any one of claims 1-5, characterized in that: Includes the following steps: S1: Preparation of unimolecular solutions and quantum dot solutions; S2: Printing a monolayer using inkjet printing technology; S3: After air drying, an isolation layer and an interference layer are sequentially prepared on a monolayer using a spin coating method.

7. The method for preparing a micro-optical anti-counterfeiting label based on single-molecule quantum coherence according to claim 6, characterized in that: The single-molecule solution and quantum dot solution were prepared by a dilution method, and the density of the single molecules and quantum dots was determined by wide-field electron multiplication EMCCD imaging to determine whether the density met the requirements.

8. A system for reading anti-counterfeiting tags prepared by the method for preparing micro optical anti-counterfeiting tags based on single-molecule quantum coherence according to claim 6 or 7, characterized in that: The system comprises an optical path section and an electrical control section. The optical path section employs a femtosecond dual-pulse pump-probe module. The electrical control section includes a time delay control module, a phase modulation module, and a PC terminal. The femtosecond dual-pulse pump-probe module includes a femtosecond laser. After polarization purification by a polarizing beam splitter, the femtosecond laser is split into two paths by a first reflecting mirror and a first unpolarizing beam splitter. One path passes through an electro-optic modulation crystal and is emitted to a fourth reflecting mirror, where the phase modulation module controls the voltage magnitude and frequency applied to the EOM. The other path is transmitted to a fourth reflecting mirror fixed on a stepper motor. Three reflecting mirrors; the two reflected signals are combined by the first unpolarized beam splitter, then pass through the first filter, the first beam expander, and the second unpolarized beam splitter before being focused onto the surface of the anti-counterfeiting label by the objective lens. The fluorescence signal of the molecules on the anti-counterfeiting label is collected by the objective lens, then passes through the second unpolarized beam splitter, the second filter, the second beam expander, and the lens to be focused onto the EMCCD optical receiving surface and transmitted to the PC. The time delay control module outputs voltage information to adjust the moving speed of the stepper motor, thereby adjusting the position of the third reflecting mirror to ensure that the Michelson interference optical path is at the 0-delay position.

9. A reading system for a micro-optical anti-counterfeiting label based on single-molecule quantum coherence according to claim 8, characterized in that: On the PC, a discrete Fourier transform is performed on the photon arrival time sequence of each pixel; the frequency domain image is redrawn using the modulation intensity at the modulation frequency as a parameter, thus completing the reading of the anti-counterfeiting label.

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