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

Abstract

The invention provides a miniature optical anti-counterfeit label based on single-molecule quantum coherence and a reading system and a preparation method thereof, and belongs to the technical field of miniature optical anti-counterfeit labels. The problems that a traditional micro optical anti-counterfeit label technology is high in preparation cost, prone to being damaged, prone to being interfered by the environment and the like are solved. Anti-counterfeiting information is constructed through spatial distribution of single molecules by utilizing an ink-jet printing technology; the inherent coherent characteristic of a single molecule is used as an anti-counterfeiting information carrier; single-molecule coherent dynamic evolution is detected through a femtosecond double-pulse pumping detection technology; extracting modulation intensity through DFT (Discrete Fourier Transform) to realize frequency domain imaging; the anti-noise capability and the information hiding capability of the anti-counterfeit label are improved by adding the quantum dots on the single molecules as interference signals.

Description

Technical Field

[0001] The invention provides a micro optical anti-counterfeiting label based on single molecule quantum coherence and a reading system and a preparation method thereof, belonging to the technical field of micro optical anti-counterfeiting labels. Background Art

[0002] With the continuous development of big data and the deepening of micro-dynamics research, more and more micro-electronic components and biometric technologies have been developed. However, counterfeit and shoddy products have always been pests that affect market order, undermine the economy, and threaten human health. Anti-counterfeiting technology is the key to ensuring product safety and traceability. Among the many anti-counterfeiting technologies, optical labels have attracted much attention due to their complex material composition and optical properties. This makes optical anti-counterfeiting labels difficult to copy and reproduce, thereby preventing counterfeiting and tampering. This technology has a wide range of applications in various fields, including protecting high-value goods and improving the safety of medicines and foods. In addition, it has also promoted the advancement of related fields such as display technology and optical imaging.

[0003] Among the various optical anti-counterfeiting technologies currently under investigation, fluorescent labels and photochromic labels have become particularly promising candidates. However, the optical materials used in this method are expensive to prepare, susceptible to physical damage, broad-spectrum and environmentally sensitive, which together make the generated signals difficult to distinguish with fidelity and security. In addition, the presence of external background information can easily drown out the encoded signal, thus bringing challenges to the preparation, storage and use of anti-counterfeiting labels. Summary of the invention

[0004] In order to solve the problems of high preparation cost, susceptibility to damage, and susceptibility to environmental interference in traditional micro-optical anti-counterfeiting label technology, the present invention proposes a micro-optical anti-counterfeiting label based on single molecule quantum coherence, a reading system and a preparation method thereof.

[0005] The technical solution adopted by the present invention is: a micro-optical anti-counterfeiting label based on single-molecule quantum coherence, including a glass slide, on which a single-molecule layer, an isolation layer and an interference layer are arranged in sequence, a single-dye molecule pattern carrying anti-counterfeiting label information is distributed on the monomolecule layer, and quantum dots serving as interference information are distributed on the interference layer.

[0006] Furthermore, the anti-counterfeiting label information in the monomolecular layer is printed by inkjet printing technology.

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

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

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

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

[0011] A method for preparing a micro-optical anti-counterfeiting label based on single molecule quantum coherence comprises the following steps: S1: Preparation of single molecule solution and quantum dot solution; S2: Printing monolayers using inkjet printing technology; S3: After natural air drying, an isolation layer and an interference layer are sequentially prepared on the monolayer by spin coating.

[0012] Furthermore, the single molecule solution and quantum dot solution are prepared by a dilution method, and wide-field electron multiplication EMCCD imaging is used to determine whether the single molecule and quantum dot densities meet the requirements.

[0013] A system for reading anti-counterfeiting labels prepared by a preparation method of a micro-optical anti-counterfeiting label based on single-molecule quantum coherence, comprising an optical path part and an electrical control part, wherein the optical path part adopts a femtosecond double-pulse pump detection module, and the electrical control part comprises a time delay control module, a phase control module and a PC end, wherein the femtosecond double-pulse pump detection module comprises a femtosecond laser, which is polarized by a polarization beam splitter and then divided into two paths by a first reflector and a first non-polarization beam splitter, wherein one path is emitted to a fourth reflector after passing through an electro-optical modulation crystal, and the voltage magnitude and the phase control module are controlled by the voltage control module loaded on the EOM. frequency, and the other is sent to a third reflector fixed on the stepper motor; the two reflected signals are combined by the first non-polarizing beam splitter and then pass through the first filter, the first beam expander, the second non-polarizing beam splitter and then converged on the surface of the anti-counterfeiting label through the objective lens; the fluorescence signal of the molecules on the anti-counterfeiting label is collected by the objective lens and then passes through the second non-polarizing beam splitter, the second filter, the second beam expander and the lens to converge on the EMCCD optical receiving surface and transmit to the PC end; 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.

[0014] Furthermore, the PC performs a discrete Fourier transform on the photon arrival time series of each pixel, redraws the frequency domain imaging with the modulation intensity at the modulation frequency as a parameter, and completes the reading of the anti-counterfeiting label.

[0015] The beneficial effects of the present invention compared to the prior art are as follows: the micro-optical anti-counterfeiting label based on single-molecule quantum coherence provided by the present invention realizes the editing and reading of anti-counterfeiting labels at the single-molecule level, and effectively improves product safety. Among them, the single-molecule anti-counterfeiting label is edited by inkjet printing technology; quantum dots are added to the upper layer of the single-molecule label as interference signals by spin coating; the influence of the interference layer quantum dots on the single-molecule label during the preparation process is avoided by inserting PMMA film and glycerol-based fluorescence quenching inhibitor between the layers; single-molecule coherent superposition states are prepared by femtosecond double pulses with adjustable delay phase; and the reading of encoded information is completed by quantum coherent imaging modulation and demodulation. The present invention uses the inherent coherence characteristics of single molecules to design optical anti-counterfeiting labels, which can be widely used in biology, medicine, food safety and other fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The present invention will be further described below in conjunction with the accompanying drawings: Figure 1 is a structural diagram of the anti-counterfeiting label prepared in this embodiment; Figure 2 is a structural diagram of the reading system in this embodiment; Figure 3 This is a result diagram of the anti-counterfeiting label writing and reading simulation using numerical simulation; Figure 4 Results of an optical anti-counterfeiting experiment conducted to verify the effectiveness of the anti-counterfeiting label of this embodiment; In the figure: 101 is a polarization beam splitter, 1021 is a first reflector, 1022 is a second reflector, 1023 is a third reflector, 1024 is a fourth reflector, 1031 is a first non-polarization beam splitter, 1032 is a second non-polarization 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 stepping motor. DETAILED DESCRIPTION

[0017] like Figures 1 to 4 As shown, the present invention provides a micro-optical anti-counterfeiting label based on single-molecule quantum coherence, which comprises a glass slide, a single-molecule layer, a sandwich isolation layer and an interference layer from bottom to top, wherein the single-molecule layer is prepared by inkjet printing technology, the sandwich isolation layer is prepared by spin coating, the three-layer material is PMMA / glycerol-based sealing agent / PMMA, and the top interference information is quantum dots prepared by spin coating. The anti-counterfeiting label of the present invention uses the single-molecule quantum coherence characteristics to carry label information, hides the information carried by the single molecule under the interference information through sample preparation, and reads the single-molecule coherent modulation signal through femtosecond double-pulse pump detection technology.

[0018] The optional single molecules of the monolayer include dye molecules such as Cy5, SR, and Terrylene.

[0019] The sandwich isolation layer is specifically: PMMA film, glycerol-based anti-fading sealing agent, PMMA film, and the thickness of each film is controlled at 1-20nm. All layers are prepared by spin coating. The first layer of PMMA film is used to prevent the monolayer from being dispersed by the glycerol-based anti-fading sealing agent. The glycerol-based anti-fading sealing agent is used to protect the monomolecule from external factors such as the environment and light, thereby reducing molecular quenching; the second layer of PMMA film is used to prevent the quantum dot solvent from reacting with the glycerol-based anti-fading sealing agent to affect the anti-fading effect.

[0020] The optional quantum dots of the interference layer include II-VI group quantum dots: such as CdSe, CdTe, ZnS, etc.

[0021] The present 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: S1: Preparation of single molecule solution and quantum dot solution; S2: Printing monolayers using inkjet printing technology; S3: After natural air drying, a sandwich isolation layer and an interference layer are sequentially prepared on the monolayer by spin coating.

[0022] The single molecule solution and quantum dot solution were prepared by dilution method.

[0023] The specific single molecule solution is obtained by dissolving the dye molecules in dimethyl sulfoxide (DMSO) solution and continuously diluting to the appropriate concentration by adding water. The diluted single molecule solution is then dropped onto the confocal slide, and after natural air drying, wide-field electron multiplication EMCCD imaging is used to determine the appropriate concentration, which requires that the molecules can be distributed individually and the molecular density is 1-30 / μm 2 .

[0024] The quantum dot solution is obtained by dissolving the quantum dots in a dimethyl sulfoxide (DMSO) solution and continuously diluting it to a suitable concentration by adding water. The concentration distribution is determined by wide-field EMCCD imaging, and interference information is prepared on the sandwich isolation layer by spin coating. The density of quantum dots after spin coating is required to be 1-30 / μm 2 .

[0025] Monolayers were printed on confocal slides using an inkjet printer with a printing resolution of ≤20 μm.

[0026] In the application of anti-counterfeiting labels, the wide-field imaging of anti-counterfeiting labels can be collected by femtosecond dual-pulse pump-detection technology, and the photon arrival sequence of each pixel can be processed by DFT transformation and the modulation intensity can be extracted. The modulation intensity of each pixel is used to draw the real label information. Therefore, the present invention also proposes a reading system for micro-optical anti-counterfeiting labels based on single-molecule quantum coherence, including an optical path part and an electrical control part. The optical path part realizes wide-field imaging of anti-counterfeiting labels through a femtosecond dual-pulse pump-detection module, and the electrical control part includes a time delay control module, a phase control module, and a PC terminal.

[0027] The structure of the femtosecond dual-pulse pump-probe module is as follows: Figure 2 In the optical path in the rectangular frame, the femtosecond laser is polarized by the polarization beam splitter 101 and then divided into two paths by the first reflector 1021 and the first non-polarization beam splitter 1031. One path is emitted to the fourth reflector 1024 after passing through the EOM, and the voltage and frequency loaded on the EOM are controlled by the phase control module. The other path is sent to the third reflector 1023 fixed on the stepper motor 110. The two reflected signals are merged by the first non-polarization beam splitter 1031, and then pass through the first filter 1061, the first beam expander 1071 and other components, and then converge on the sample surface through the objective lens 108. The fluorescence signal of the molecule is collected by the objective lens 108, and then converged on the EMCCD optical receiving surface through the second filter 1062, the second beam expander 1072 and the lens 109 and transmitted to the PC end.

[0028] The time delay control module outputs voltage information to adjust the position of the third reflector 1023 on the stepper motor 110 to ensure that the Michelson interference optical path is at the zero delay position. The phase control module is composed of a signal generator 104 and a high-voltage amplifier 105, which is used to control the voltage signal loaded on the EOM, thereby adjusting the phase of the EOM output signal. The PC end is provided with a data acquisition module and a data processing module, wherein the data acquisition module is composed of a Labview program and Andor spectrometer software.

[0029] The present invention will be further described below based on the embodiments in the accompanying drawings.

[0030] refer to Figure 1-3 The present embodiment provides a micro optical anti-counterfeiting label based on single molecule quantum coherence, and the steps of preparing the label and reading the anti-counterfeiting information are as follows: Step 1: Preparation of micro single-molecule anti-counterfeiting labels; Step 1.1: Prepare SR single molecule solution and CdTeSe / ZnS QDs@800nm ​​(800QDs) solution by solution method; Step 1.2: Prepare an “H”-shaped SR single-molecule labeling pattern on a confocal slide by inkjet printing technology; Step 1.3: Prepare a sandwich isolation layer by spin coating, where the PMMA concentration is 2%, the spin coating parameters are 3000 rpm, 30 seconds, dry at room temperature for 10 minutes, and then bake at 80°C for 30 minutes. Glycerol-based antifade mounting agent is drop-coated on the PMMA film, and squeezed into shape by adding a cover glass on top. After 2 hours, the cover glass on top is removed, and the next layer of PMMA film is spin-coated according to the above method after standing in a drying oven for 24 hours; Step 1.4: Prepare interference information on the above sample by spin coating. In this embodiment, 800 QDs are selected as the interference layer, and the spin coating parameters are: ① 500 rpm, 5 s; ② 1500 rpm, 10 s; ③ 3000 rpm, 30 s.

[0031] Step 2: Use a femtosecond dual-pulse pump-probe system to collect wide-field imaging of single-molecule anti-counterfeiting labels; Step 2.1: The signal generator 104 and the high-voltage amplifier 105 control the sawtooth wave electrical signal loaded on the EOM so that the EOM output signal is positive rotation; Step 2.2: After the polarization of the femtosecond laser is purified by the polarization beam splitter 101, it is divided into two paths by the first reflector 1021 and the first non-polarization beam splitter 1031. One path is emitted to the fourth reflector 1024 after passing through the EOM, and the other path is sent to the third reflector 1023 fixed on the stepper motor 110. The two reflected signals reflected by the third reflector 1023 and the fourth reflector 1024 are combined by the first non-polarization beam splitter 1031 and then reflected by the second reflector 1022. Then, the reflected signal passes through the first filter 1061, the first beam expander 1071, and the second non-polarization beam splitter 1032 and converges on the sample surface through the objective lens 108; Step 2.3: The fluorescence signal of the molecule is collected by the objective lens 108 and then converged on the EMCCD optical receiving surface through the second non-polarizing beam splitter 1032, the second filter 1062, the second beam expander 1071 and the lens 109 and transmitted to the PC end.

[0032] Step 3: Read the anti-counterfeiting label information; Step 3.1: The PC performs a discrete Fourier transform (DFT) on the photon arrival time series for each pixel; Step 3.2: Redraw the frequency domain imaging with the modulation intensity at the modulation frequency as a parameter to complete the reading of the anti-counterfeiting label.

[0033] The effectiveness of the present invention is verified by experiments below: Figure 1This is the structural diagram of the designed anti-counterfeiting label, which includes, from bottom to top, a glass slide, a SR single-molecule label, a sandwich isolation layer and interference information. The SR single-molecule layer is prepared by inkjet printing technology, the sandwich isolation layer is prepared by spin coating, and the three-layer materials are PMMA / glycerol sealing agent / PMMA. The top interference information is CdTeSe / ZnSQDs@800nm, 800QDs prepared by spin coating.

[0034] Figure 2 For the experimentally designed reading system, the output signal of the signal generator 104 in the experiment of this embodiment is a sawtooth wave with a voltage of 136V and a frequency of 5Hz.

[0035] Figure 3 The results of simulating the writing and reading of the anti-counterfeiting label mentioned above are simulated by numerical simulation. Figure 3 (a), (b), and (c) correspond to the sample with only SR molecules, the sample with SR molecules and 800 QDs, and the single-molecule quantum coherence signal extracted using discrete Fourier transform, respectively. Figure 3 In (a), a coding character region (“pseudo”) is selected in the image, and 50 coordinate points are randomly selected from this region. With these coordinate points as the center, a circular region is selected to represent a single molecule, with a radius of 3 or 4 pixels. Based on the original coding data, the entire region is selected to load interference information, and 300 coordinate points are randomly selected to perform the above simulation process. It should be noted that this part of the photons is not frequency modulated (800 QDs), as shown in Figure 3 (b) is shown. The present invention is Figure 3 In (a), each pixel point in the circular area establishes a photon response time axis during the EMCCD exposure time, where the probability of detecting a photon at different times obeys a certain modulation frequency. Photons are counted on each time axis, and the count value is used as the light intensity value of the corresponding pixel to obtain the original coded data. Then, a DFT transform is performed on each time axis, and the modulation factor is converted and used as the value of the corresponding pixel to obtain the frequency domain imaging of the coded area that only retains the modulation information, such as Figure 3 (c) as shown.

[0036] Figure 4 This is a demonstration of micro-optical anti-counterfeiting experiment based on single-molecule quantum coherence. Figure 4 (a) is a wide-field fluorescence imaging image of a single-molecule tag “H” prepared only by inkjet printing. Figure 4 (b) Wide-field imaging of the sample after preparing a sandwich isolation layer and 800 QDs on the upper layer of the single-molecule label “H”. It can be seen that in the fluorescence imaging, the label “H” is hidden and cannot be read by conventional means. Figure 4 (c) Figure 4(b) shows the frequency domain imaging of the sample. Since the complex dynamic process inside the quantum dot overwhelms its quantum coherent information, the quantum dot interference signal disappears, and the single molecule label "H" is successfully read with an identification 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 label proposed by the present invention.

[0037] The present invention utilizes inkjet printing technology to construct anti-counterfeiting information through the spatial distribution of single molecules; utilizes the inherent coherence characteristics of single molecules as the carrier of anti-counterfeiting information; detects the coherent dynamic evolution of single molecules through femtosecond double-pulse technology; realizes frequency domain imaging by extracting modulation intensity through DFT transformation; and improves the anti-noise ability and information hiding ability of anti-counterfeiting labels by adding quantum dots as interference signals on single molecules.

[0038] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements 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: A monomolecular layer, an isolation layer and an interference layer are sequentially arranged on the glass slide; a single dye molecule pattern carrying anti-counterfeiting label information is distributed on the monomolecular layer; and quantum dots serving as interference information are distributed on the interference layer.

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 monomolecular layer is printed by inkjet printing technology.

3. The micro optical anti-counterfeiting label based on single molecule quantum coherence according to claim 2, characterized in that: The monolayer is made of single dye molecules of Cy5, SR or Terrylene, with a molecular density of 1-30 per μm 2 .

4. The micro optical anti-counterfeiting label based on single molecule quantum coherence according to claim 1, characterized in that: The isolation layer is a sandwich isolation layer, including a PMMA film, a glycerol-based anti-fading sealing agent, and a PMMA film.

5. The micro optical anti-counterfeiting label based on single molecule quantum coherence according to claim 4, characterized in that: The thickness of each layer of the sandwich isolation layer is 1-20 nm.

6. The micro optical anti-counterfeiting label based on single molecule quantum coherence according to claim 1, characterized in that: The quantum dots are selected from group II-VI quantum dots, and the density of the quantum dots is 1-30 / μm 2 .

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

8. The method for preparing a micro optical anti-counterfeiting label based on single molecule quantum coherence according to claim 7, characterized in that: The single molecule solution and quantum dot solution are prepared by a dilution method, and wide-field electron multiplication EMCCD imaging is used to determine whether the single molecule and quantum dot densities meet the requirements.

9. A system for reading an anti-counterfeiting label prepared by the method for preparing a micro-optical anti-counterfeiting label based on single molecule quantum coherence according to claim 7 or 8, characterized in that: The invention comprises an optical path part and an electrical control part, wherein the optical path part adopts a femtosecond double-pulse pump detection module, the electrical control part comprises a time delay control module, a phase control module and a PC end, the femtosecond double-pulse pump detection module comprises a femtosecond laser, and the femtosecond laser is polarized by a polarization beam splitter and then divided into two paths by a first reflector and a first non-polarization beam splitter, one of which is emitted to a fourth reflector after passing through an electro-optical modulation crystal, and the voltage and frequency loaded on the EOM are controlled by the phase control module, and the other is sent to a first fixed on a stepping motor. Three reflectors; the two reflected signals are combined by the first non-polarizing beam splitter and then pass through the first filter, the first beam expander, the second non-polarizing beam splitter and then converged on the surface of the anti-counterfeiting label through the objective lens; the fluorescence signals of the molecules on the anti-counterfeiting label are collected by the objective lens and then pass through the second non-polarizing beam splitter, the second filter, the second beam expander and the lens to converge on the EMCCD optical receiving surface and transmit to the PC end; the time delay control module outputs voltage information to adjust the moving speed of the stepping motor, thereby adjusting the position of the third reflector to ensure that the Michelson interference optical path is at the 0 delay position.

10. The reading system of a micro optical anti-counterfeiting label based on single molecule quantum coherence according to claim 9, characterized in that: The PC end performs discrete Fourier transform on the time series of photon arrival at each pixel, redraws the frequency domain imaging with the modulation intensity at the modulation frequency as a parameter, and completes the reading of the anti-counterfeiting label.

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