Non-contact light force and temperature measurement integrated system and method

Abstract

The invention specifically discloses a non-contact light force and temperature measurement integrated system and method, and relates to the technical field of optical measurement and sensing. The system comprises an excitation light path module which is used for providing a laser light source with the wave band of 976.5 nm; the sample chamber module is internally provided with a solution containing up-conversion nanoparticles highly doped with lanthanide ions, and a sample chamber can be quickly replaced and fixed on the sample table; the imaging light path module comprises an optical filter, an optical splitter and an image acquisition device; the data processing module is used for calculating the potential well rigidity of the optical tweezers based on the Brownian motion trail of the captured particles and calculating the light force in combination with the displacement offset; and through the fluorescence intensity ratio of the wave band of 520 nm to the wave band of 550 nm, environment temperature information is obtained by contrasting with a pre-calibrated ratio-temperature relation curve. According to the method, high-precision light force information and temperature information can be obtained at the same time, the problem of single measurement in traditional biological cell measurement is solved, and comprehensive measurement is achieved.

Description

Technical Field

[0001] The present invention relates to the field of optical measurement and sensing technology, and in particular to a non-contact optical force and temperature measurement integrated system and method. Background Art

[0002] Optical tweezers, a cutting-edge and critical technological tool, plays a vital role in the study of the microscopic world. Optical tweezers utilize a highly focused laser beam to construct a gradient potential field with unique properties at its focal region. This gradient potential field acts as an invisible "trap," generating a unique gradient force that enables the precise three-dimensional capture of tiny particles. Once successfully captured, a tiny particle exhibits a state of confined Brownian motion. In this state, researchers can continuously and precisely track the particle's trajectory and apply specific algorithms and mathematical models to quantitatively calculate the magnitude of the gradient force. Notably, there is a close negative correlation between the gradient force and the particle's displacement amplitude: as the gradient force increases, the particle's displacement amplitude decreases significantly; conversely, as the gradient force decreases, the particle's range of motion increases accordingly.

[0003] Upconversion nanoparticles highly doped with lanthanide ions have shown unique advantages in the application of optical tweezers technology. This type of nanoparticle can produce a resonance effect with lasers in the 980nm band. Once resonance occurs, the optical trap stiffness will be greatly increased, which allows it to be stably captured by optical tweezers. Not only that, upconversion nanoparticles also have the characteristics of high brightness. Based on this characteristic, when using video positioning technology, higher positioning accuracy can be obtained. This advantage makes it occupy an important position in the field of high-precision optical force measurement. In addition, the nanoparticle also has a unique temperature-responsive fluorescence characteristic. Under different temperature environments, the emission peak of its thermal coupling energy level will change significantly. This characteristic makes it possible to use it in the field of temperature measurement.

[0004] However, the field of traditional biological cell measurement currently faces many challenges. Most existing measurement methods can only achieve single mechanical measurement or temperature measurement, and cannot obtain two key data at the same time. If you try to perform mechanical and temperature measurements one after another, the measurement conditions are very likely to change during this process. For example, changes in the temperature and humidity of the experimental environment, changes in the physiological state of the sample itself, etc., all of these changes will have a serious impact on the accuracy of the measurement results. Moreover, when conducting mechanical and temperature measurements separately, it is often necessary to equip a variety of complex and expensive measuring equipment, which not only increases the cost of the experiment, but also makes the operation process extremely cumbersome, and requires higher professional skills from the experimenters, which to a certain extent limits the efficient development of related research. Summary of the Invention

[0005] The purpose of the present invention is to propose a non-contact integrated system and method for optical force and temperature measurement. By capturing upconversion nanoprobes with optical tweezers, the motion trajectory and fluorescence intensity information of the captured particles are comprehensively analyzed, and high-precision optical force information and temperature information are obtained simultaneously, thereby solving the problem of single measurement in traditional biological cell measurement and realizing integrated measurement.

[0006] To achieve the above objectives, the present invention proposes a non-contact optical force and temperature measurement integrated system, comprising:

[0007] The excitation optical path module is used to provide a laser light source in the 976.5nm band. The laser is reflected by the dichroic mirror and focused on the sample chamber through the microscope objective lens;

[0008] A sample chamber module, containing a solution of upconversion nanoparticles highly doped with lanthanide ions, wherein the sample chamber can be quickly replaced and fixed on the sample stage;

[0009] The imaging optical path module includes a filter, a spectrometer, and an image acquisition device, which is used to separate and collect the 520nm and 550nm fluorescence signals emitted by the upconversion nanoparticles;

[0010] The data processing module calculates the potential well stiffness of the optical tweezers based on the Brownian motion trajectory of the captured particles, and calculates the optical force in combination with the displacement offset; the ambient temperature information is obtained by comparing the fluorescence intensity ratio of the 520nm and 550nm bands with a pre-calibrated ratio-temperature relationship curve.

[0011] Preferably, the laser light source power of the excitation light path module is adjustable to adapt to the light trap stiffness requirements of different experimental scenarios.

[0012] Preferably, the beam splitter is a dichroic beam splitter or a prism beam splitter device, which is used to split the fluorescence in the 520nm and 550nm bands into different channels of the image acquisition device.

[0013] Preferably, the potential well stiffness of the optical tweezers is obtained by fitting the motion trajectory distribution of the nanoparticles, and the distance between the nanoparticles and the center is calculated as follows:

[0014]

[0015] Where P(x) is the statistical distribution probability of the particle, x is the displacement of the nanoparticle from the center point, k B is the Boltzmann constant, T is the temperature in Kelvin, and k is the potential well stiffness of the optical tweezers.

[0016] Preferably, the data processing module further includes:

[0017] The motion trajectory analysis unit uses a particle tracking algorithm to fit the displacement distribution in real time and dynamically update the potential well stiffness;

[0018] The temperature calculation unit outputs the temperature value and error range by matching the real-time fluorescence intensity ratio with the database.

[0019] Preferably, the upconversion nanoparticles are NaYF4 matrix doped with Er 3+ / Yb 3+ The fluorescence intensity ratio of the nanoparticles containing ions shows a linear or nonlinear relationship with temperature.

[0020] Preferably, the sample stage supports passive three-dimensional manipulation, and achieves stable positioning of captured particles through micron-level displacement adjustment.

[0021] Preferably, the optical filters are bandpass filters with central wavelengths of 520±5 nm and 550±5 nm respectively.

[0022] The present invention also provides a non-contact optical force and temperature measurement integrated method, comprising the following steps:

[0023] S1: Use 976.5nm laser to excite upconversion nanoparticles, and then separate the emitted fluorescence into two wavelength bands: 517.5-532.5nm and 532.5-547.5nm after passing through a filter and a spectrometer. Continuously collect fluorescence image data.

[0024] S2. Analyze the trajectory of upconversion nanoparticles, perform Gaussian fitting on their distribution, and calculate the potential well stiffness and optical force;

[0025] S3, comparing the extracted dual-band fluorescence intensities with the calibrated database output temperature value;

[0026] S4. Display and store the light force and temperature measurement results in real time.

[0027] Preferably, the calculation formula of the potential well stiffness is as follows:

[0028] k=k B T / (σ 2 P);

[0029] Where σ is the standard deviation of the particle distribution, and P is the power of the laser used in the optical tweezers.

[0030] Therefore, the present invention proposes a non-contact optical force and temperature measurement integrated system and method, which has the following beneficial effects:

[0031] (1) Functional integration advantage: The integrated measurement system of the present invention has groundbreakingly integrated the force measurement and temperature measurement functions. In the traditional measurement mode, if mechanical and temperature measurements are carried out successively, since the measurement environment is difficult to maintain constant, slight environmental changes, such as temperature fluctuations, airflow disturbances, etc., may affect the sample state, thereby causing deviations in the measurement results. However, this system can synchronously acquire optical force and temperature data at the same time and under the same environmental conditions, fundamentally avoiding errors caused by changes in measurement conditions, significantly improving the accuracy and reliability of measurements, and providing scientific researchers with more valuable data support that is closer to the real situation.

[0032] (2) Cost-effectiveness: In the past, light force and temperature measurements often required the purchase of expensive thermometers, spectrometers, and other information acquisition equipment, which undoubtedly significantly increased the cost of scientific research. However, the present invention only relies on an ordinary camera as an image acquisition device, combined with the system's core algorithms and optical components, to complete high-precision light force and temperature measurements. This design greatly reduces equipment procurement and maintenance costs, achieves powerful measurement functions with lower investment, improves the utilization efficiency of scientific research resources, and allows more scientific research teams to easily afford related experimental research.

[0033] (3) Operational convenience: The system is designed with user experience in mind. On the same device, researchers can switch freely between different measurement requirements and easily achieve mechanical and temperature measurements through a simple operation process without having to perform complex equipment modifications or parameter adjustments. This not only saves experimental preparation time and reduces possible errors due to complex operations, but also significantly improves measurement efficiency, allowing researchers to devote more time and energy to key experimental research and data analysis, accelerating the scientific research process.

[0034] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 This is a structural diagram of a non-contact optical force and temperature measurement integrated system of the present invention. DETAILED DESCRIPTION

[0036] To make the technical solutions, advantages, and objectives of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below. The described embodiments are part of the embodiments of the present invention, not all of them. Based on the described embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0037] Unless otherwise defined, technical or scientific terms used in the present invention shall have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention belongs.

[0038] Example 1

[0039] like Figure 1 FIG. 1 is a structural diagram of a non-contact optical force and temperature measurement integrated system of the present invention, comprising:

[0040] The excitation optical path module is used to provide a laser light source in the 976.5nm band. The laser is reflected by the dichroic mirror and focused on the sample chamber through the microscope objective lens;

[0041] The laser light source power of the excitation optical path module is adjustable to adapt to the light trap stiffness requirements of different experimental scenarios.

[0042] The sample chamber module contains a solution of upconversion nanoparticles highly doped with lanthanide ions. The sample chamber can be quickly replaced and fixed on the sample stage.

[0043] Upconversion nanoparticles are NaYF4 matrix doped with Er 3+ / Yb 3+ The fluorescence intensity ratio of the nanoparticles containing ions shows a linear or nonlinear relationship with temperature.

[0044] The imaging optical path module includes a filter, a spectrometer, and an image acquisition device, which is used to separate and collect the 520nm and 550nm fluorescence signals emitted by the upconversion nanoparticles;

[0045] The beam splitter is a dichroic beam splitter or a prism beam splitting device, which is used to split the fluorescence in the 520nm and 550nm bands into different channels of the image acquisition device.

[0046] The data processing module calculates the potential well stiffness of the optical tweezers based on the Brownian motion trajectory of the captured particles, and calculates the optical force in combination with the displacement offset; the ambient temperature information is obtained by comparing the fluorescence intensity ratio of the 520nm and 550nm bands with a pre-calibrated ratio-temperature relationship curve.

[0047] The potential well stiffness of the optical tweezers is obtained by fitting the motion trajectory distribution of the nanoparticles. The distance between the nanoparticles and the center is calculated as follows:

[0048]

[0049] Where P(x) is the statistical distribution probability of the particle, x is the displacement of the nanoparticle from the center point, k B is the Boltzmann constant, T is the temperature in Kelvin, and k is the potential well stiffness of the optical tweezers.

[0050] The data processing module also includes:

[0051] The motion trajectory analysis unit uses a particle tracking algorithm to fit the displacement distribution in real time and dynamically update the potential well stiffness;

[0052] The temperature calculation unit outputs the temperature value and error range by matching the real-time fluorescence intensity ratio with the database.

[0053] The sample stage supports passive three-dimensional manipulation and achieves stable positioning of captured particles through micron-level displacement adjustment.

[0054] The filters are bandpass filters with center wavelengths of 520±5nm and 550±5nm respectively.

[0055] Example 2

[0056] The present invention provides a non-contact optical force and temperature measurement integrated method, the steps are as follows:

[0057] S1: Use 976.5nm laser to excite upconversion nanoparticles, and then separate the emitted fluorescence into two wavelength bands: 517.5-532.5nm and 532.5-547.5nm after passing through a filter and a spectrometer. Continuously collect fluorescence image data.

[0058] S2. Analyze the trajectory of the upconversion nanoparticles, perform Gaussian fitting on their distribution, and calculate the potential well stiffness and optical force. The calculation formula for the potential well stiffness is as follows:

[0059] k=k B T / (σ 2 P);

[0060] Where σ is the standard deviation of the particle distribution, and P is the power of the laser used in the optical tweezers.

[0061] S3, comparing the extracted dual-band fluorescence intensities with the calibrated database output temperature value;

[0062] S4. Display and store the light force and temperature measurement results in real time.

[0063] It is worth noting that the contents not elaborated in detail in the present invention are all prior art and are well known to those skilled in the art.

[0064] Therefore, the present invention provides a non-contact integrated system and method for optical force and temperature measurement. By capturing upconversion nanoprobes with optical tweezers, the motion trajectory and fluorescence intensity information of the captured particles are comprehensively analyzed, and high-precision optical force information and temperature information are obtained simultaneously, solving the problem of single measurement in traditional biological cell measurement and realizing integrated measurement.

[0065] 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 the same. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solutions of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A non-contact optical force and temperature measurement integrated system, characterized in that: include: The excitation optical path module is used to provide a laser light source in the 976.5nm band. The laser is reflected by the dichroic mirror and focused on the sample chamber through the microscope objective lens; A sample chamber module, containing a solution of upconversion nanoparticles highly doped with lanthanide ions, wherein the sample chamber can be quickly replaced and fixed on the sample stage; The imaging optical path module includes a filter, a spectrometer, and an image acquisition device, which is used to separate and collect the 520nm and 550nm fluorescence signals emitted by the upconversion nanoparticles; The data processing module calculates the potential well stiffness of the optical tweezers based on the Brownian motion trajectory of the captured particles, and calculates the optical force in combination with the displacement offset; the ambient temperature information is obtained by comparing the fluorescence intensity ratio of the 520nm and 550nm bands with a pre-calibrated ratio-temperature relationship curve.

2. A non-contact optical force and temperature measurement integrated system according to claim 1, characterized in that: The laser light source power of the excitation light path module is adjustable to adapt to the light trap stiffness requirements of different experimental scenarios.

3. The non-contact optical force and temperature measurement integrated system according to claim 1, characterized in that: The beam splitter is a dichroic beam splitter or a prism beam splitter device, which is used to split the fluorescence in the 520nm and 550nm bands into different channels of the image acquisition device.

4. The non-contact optical force and temperature measurement integrated system according to claim 1, characterized in that: The potential well stiffness of the optical tweezers is obtained by fitting the motion trajectory distribution of the nanoparticles. The distance between the nanoparticles and the center is calculated as follows: Where P(x) is the statistical distribution probability of the particle, x is the displacement of the nanoparticle from the center point, k B is the Boltzmann constant, T is the temperature in Kelvin, and k is the potential well stiffness of the optical tweezers.

5. The non-contact optical force and temperature measurement integrated system according to claim 1, characterized in that: The data processing module also includes: The motion trajectory analysis unit uses a particle tracking algorithm to fit the displacement distribution in real time and dynamically update the potential well stiffness; The temperature calculation unit outputs the temperature value and error range by matching the real-time fluorescence intensity ratio with the database.

6. The non-contact optical force and temperature measurement integrated system according to claim 1, characterized in that: Upconversion nanoparticles are NaYF4 matrix doped with Er 3+ / Yb 3+ The fluorescence intensity ratio of the nanoparticles containing ions shows a linear or nonlinear relationship with temperature.

7. The non-contact optical force and temperature measurement integrated system according to claim 1, characterized in that: The sample stage supports passive three-dimensional manipulation and achieves stable positioning of captured particles through micron-level displacement adjustment.

8. The non-contact optical force and temperature measurement integrated system according to claim 1, characterized in that: The optical filters are bandpass filters with central wavelengths of 520±5nm and 550±5nm respectively.

9. A non-contact optical force and temperature measurement integrated method, characterized in that: The following steps are involved: S1: Use 976.5nm laser to excite upconversion nanoparticles, and then separate the emitted fluorescence into two wavelength bands: 517.5-532.5nm and 532.5-547.5nm after passing through a filter and a spectrometer. Continuously collect fluorescence image data. S2. Analyze the trajectory of upconversion nanoparticles, perform Gaussian fitting on their distribution, and calculate the potential well stiffness and optical force; S3, comparing the extracted dual-band fluorescence intensities with the calibrated database output temperature value; S4. Display and store the light force and temperature measurement results in real time.

10. The non-contact optical force and temperature measurement integrated method according to claim 9, characterized in that: The calculation formula of potential well stiffness is as follows: k=k B T / (σ 2 P); Where σ is the standard deviation of the particle distribution, and P is the power of the laser used in the optical tweezers.

Images