Particle thermodynamic measurement method and device based on double-laser confocal microscopy

Abstract

The present application relates to the field of nanoscience and nanotechnology, and particularly relates to a particle thermodynamic measurement method and device based on double laser confocal microscopy, in which a high-power continuous laser is used as a trapping laser to trap particles in a solution, and the movement of the particles in the trapping process is monitored in real time, the force acting on the particles is analyzed according to the movement trajectory of the particles, then a low-power continuous laser is used as a Raman detection laser to focus on the trapped particles to excite Raman signals, and Raman spectroscopy is used to quantify the temperature of the particles to perform particle thermometric measurement and realize thermodynamic measurement of the particles. The method of the present application can be used in the field of physics to study the thermodynamic coupling problem in optical tweezers trapping, can be used in the field of biology to achieve precise trapping of cells or microorganisms under low heat, and can be used in the field of energy utilization to realize efficient utilization of energy by precisely regulating the thermodynamic properties of micro-nano structures.

Description

Technical Field

[0001] This invention relates to the fields of nanoscience and nanotechnology, and specifically to a method and apparatus for measuring particle thermodynamics based on dual-laser confocal microscopy. Background Technology

[0002] Optical tweezers are a technique for precisely capturing and manipulating tiny particles using optical forces generated by light intensity gradients and photon momentum transfer. They have attracted considerable interest across various cutting-edge disciplines, including biology, physics, nanoscience, and nanotechnology. In optical tweezers, achieving stable capture of objects requires a high-power-density light field at the focal plane to generate a strong gradient force. However, the thermal effects on the sample caused by high-power-density laser irradiation are unavoidable.

[0003] In recent years, the thermal effects of optical tweezers have been a focus of research, leading to numerous theoretical models and experimental schemes to quantify the temperature rise of particles induced by optical tweezer lasers. For example, researchers have studied the temperature of trapped particles in water based on Brownian motion spectra. In a recent study, researchers pointed out that temperature affects the dynamics of colloidal nanoparticles. Despite some experimental studies on the thermal effects of particles in optical tweezers, there are currently no experimental studies on in-situ measurements of the heat and force of trapped particles.

[0004] Since the advent of optical tweezers, its application in mechanical analysis has been the subject of numerous experimental studies. Current research primarily utilizes the Stokes drag method, instantaneous displacement method, and power spectral analysis. This demonstrates that mechanical analysis using optical tweezers is relatively mature. However, combining optical tweezers with temperature measurement still requires overcoming significant technical hurdles, such as measurement accuracy, sensitivity, and high spatial resolution.

[0005] Therefore, it is essential to develop a thermodynamic in-situ measurement method for photo-trapping particles. Summary of the Invention

[0006] One of the objectives of this invention is to provide a particle thermodynamic measurement method based on dual-laser confocal microscopy, which can simultaneously measure the temperature and force of captured particles. This is crucial for studying the impact of particle thermal effects on the performance of optical tweezers manipulation.

[0007] The second objective of this invention is to provide a particle thermodynamic measurement device based on dual-laser confocal microscopy technology, which is used to implement the method, has a simple structure, low cost, and is easy to use.

[0008] One of the solutions adopted to achieve the objective of this invention is: a particle thermodynamic measurement method based on dual-laser confocal microscopy. In the solution, a high-power continuous laser is used as the capturing laser to capture particles, and the movement of the particles during the capture process is monitored in real time. The force on the particles is analyzed based on the particle's motion trajectory. Then, a low-power continuous laser is used as the Raman detection laser and focused on the captured particles to excite Raman signals. Raman spectroscopy is used to quantify the temperature of the particles and perform particle thermal measurement, thereby realizing the thermodynamic measurement of particles.

[0009] Preferably, the procedure specifically includes the following steps:

[0010] Prepare a solution containing particles and pour the solution into a transparent container;

[0011] A high-power continuous laser is focused onto the surface at the bottom of the container to capture particles. During the capture process, the real-time movement of the particles is monitored, and the velocity of the particles escaping the trap is obtained based on the particle's trajectory. Then, the optical force of the particles is obtained based on the Stokes drag method.

[0012] A low-power continuous laser is focused onto the captured particles to excite Raman signals, and Raman spectroscopy is used to quantify the temperature of the particles; thus, particle thermal measurement is performed.

[0013] Preferably, the refractive index of the particles is greater than that of the surrounding medium, and they have Raman signals; the particle size is micro-nano particles.

[0014] Preferably, the particles are microplastic particles, biological cells, or DNA molecules.

[0015] Preferably, the wavelength of the high-power continuous laser is 1064 nm and the power is 0.138-0.304 W.

[0016] Preferably, the force situation of the particle is analyzed by Stokes drag method based on the particle's motion trajectory.

[0017] Preferably, the low-power continuous laser wavelength is 532 nm and the power is 1.06-3.95 mW.

[0018] Preferably, the high-power continuous laser and the low-power laser are in a confocal state.

[0019] The solution adopted to achieve the second objective of this invention is: a particle thermodynamic measurement device based on dual-laser confocal microscopy technology, used in the method, comprising a Raman capture unit and a Raman detection unit, wherein the capture unit comprises a high-power continuous laser and a high-speed camera, and the Raman detection unit comprises a low-power continuous laser and a Raman spectrometer, wherein the lasers emitted by the high-power continuous laser and the low-power continuous laser are in a confocal state during use.

[0020] Preferably, a filter is added at the exit of the low-power continuous laser. The filter is used to filter the 1064 nm laser while ensuring the passage of the Raman scattering signal.

[0021] The present invention has the following advantages and beneficial effects:

[0022] The particle thermodynamic measurement method based on dual-laser confocal microscopy of the present invention can realize the measurement of the heat and force of captured particles.

[0023] The particle thermodynamic measurement method based on dual-laser confocal microscopy of the present invention can realize non-contact and high-precision measurement of particle temperature and force.

[0024] The particle thermodynamic measurement method based on dual-laser confocal microscopy of the present invention can be used to analyze the influence of thermal effects on particle capture.

[0025] The method of this invention can be used in the field of physics to study the thermo-coupling problem in optical tweezers capture; it can be used in the field of biology to achieve precise capture of cells or microorganisms under low-heat conditions; and it can be used in the field of energy utilization to achieve efficient energy utilization by precisely controlling the thermodynamic properties of micro- and nano-structures.

[0026] The particle thermodynamic measurement device based on dual-laser confocal microscopy technology of the present invention has a simple structure, low cost, and is easy to operate. Attached Figure Description

[0027] Figure 1 The diagram shows a schematic representation of the particle thermodynamic measurement device based on dual-laser confocal microscopy technology of the present invention.

[0028] Figure 2 It is the maximum speed at which the optical trap of PS particles escapes from the image recorded by the camera in Example 2;

[0029] Figure 3 The Raman signal of the trapped polystyrene (PS) particles measured by the particle thermodynamic measurement method based on dual-laser confocal microscopy in Example 2;

[0030] Figure 4 This is a thermal response diagram of captured polystyrene (PS) particles measured by the particle thermodynamic measurement method based on dual-laser confocal microscopy in Example 2. In this diagram, a is the relationship between capture power and Raman displacement of PS particles, and b is the relationship between capture power and temperature rise of PS particles after considering the temperature-displacement coefficient.

[0031] Figure 5This is a thermal response diagram of captured polyethylene (PE) particles measured by the particle thermodynamic measurement method based on dual-laser confocal microscopy in Example 3, where a is the Raman spectrum of PE particles under different capture powers, and b is the relationship between capture power and Raman shift of PE particles.

[0032] Figure 6 This is a thermal response diagram of the chemical substances in the captured biological grinding fluid measured by the particle thermodynamic measurement method based on dual-laser confocal microscopy in Example 4. In this diagram, a is the Raman spectrum of biological DNA under different capture powers, and b is the relationship between capture power and Raman shift of biological DNA.

[0033] In the diagram, 1 is a high-power continuous laser, 2 is a high-speed camera, 3 is the first objective lens, 4 is a dichroic mirror, 5 is a low-power continuous laser, 6 is a Raman spectrometer, 7 is the second objective lens, and 8 is a filter. Detailed Implementation

[0034] To better understand the present invention, the following embodiments are further illustrations of the present invention, but the content of the present invention is not limited to the following embodiments.

[0035] A particle thermodynamic measurement method based on dual-laser confocal microscopy is proposed. In solution, a high-power continuous laser is used as the capturing laser to capture particles, and the movement of the particles during the capture process is monitored in real time. The force on the particles is analyzed based on the particle's motion trajectory. Then, a low-power continuous laser is used as the Raman detection laser and focused on the captured particles to excite Raman signals. Raman spectroscopy is used to quantify the temperature of the particles and perform particle thermal measurement, thus realizing the thermodynamic measurement of particles.

[0036] Specifically, the following steps are included:

[0037] Prepare a solution containing particles and pour the solution into a transparent container;

[0038] A high-power continuous laser is focused onto the surface at the bottom of the container to capture particles. During the capture process, the real-time movement of the particles is monitored, and the velocity of the particles escaping the trap is obtained based on the particle's trajectory. Then, the optical force of the particles is obtained based on the Stokes drag method.

[0039] A low-power continuous laser is focused onto the captured particles to excite Raman signals, and Raman spectroscopy is used to quantify the temperature of the particles; thus, particle thermal measurement is performed.

[0040] Example 1

[0041] like Figure 1As shown, a particle thermal measurement device based on dual-laser confocal microscopy technology includes a Raman capture unit and a Raman detection unit. The capture unit includes a high-power continuous laser 1 and a high-speed camera 2, and the Raman detection unit includes a low-power continuous laser 5 and a Raman spectrometer 6. In use, the lasers emitted by the high-power continuous laser 1 and the low-power continuous laser 5 are in a confocal state.

[0042] A filter is added at the exit of the low-power continuous laser, and the filter is used to filter the 1064 nm laser.

[0043] In this embodiment, the high-power continuous laser 1 emits a continuous laser beam at 1064 nm with a power of 0.138-0.304 W.

[0044] In this embodiment, the low-power continuous laser 5 emits a 532 nm continuous laser with a power of 1.06-3.95 mW.

[0045] In this embodiment, the high-speed camera 2 is a CMOS camera.

[0046] During operation, a quartz glass container holds the particle solution. A 1064 nm capturing laser emitted by a high-power continuous laser 1 is refracted by a dichroic mirror 4 and focused onto the bottom surface of the quartz glass container by a first objective lens 3, forming a large optical field gradient that can capture micro- and nano-particles. A high-speed camera 2 monitors the real-time motion of the particles through the first objective lens and analyzes the force on the particles based on the Stokes drag method. A 532 nm laser emitted by a low-power continuous laser 5 is focused onto the captured particles by a second objective lens 7 to excite Raman signals and is confocalized with the 1064 nm laser. The Raman signal enters the Raman spectrometer 6 along the optical fiber. The temperature of the particles is quantified based on Raman spectroscopy, realizing the thermodynamic measurement of the particles. A specific filter 8 is set at the exit of the second objective lens to filter the 1064 nm laser.

[0047] Example 2

[0048] A particle thermodynamic measurement method based on dual-laser confocal microscopy includes the following steps:

[0049] 1. Prepare a PS (polystyrene) particle dispersion with a concentration of 0.05-0.2 mg / ml and place it in a quartz glass container. The PS particle size is 0.1-5 μm.

[0050] 2. A 1064 nm continuous laser is focused onto the inner surface of the bottom of the quartz glass through the first objective lens to form a large light field gradient, which can capture PS particles; a CMOS camera monitors the real-time movement of the particles through the first objective lens;

[0051] The movement of a quartz dish containing PS solution is controlled by moving a precision displacement stage until the particles escape the control of the optical trap. Based on this method, the maximum escape velocity (0.138-0.304 W) can be obtained at different trapping laser powers.

[0052] 3. A 532 nm continuous laser is focused onto the captured PS particles through a second objective lens to excite their Raman signals, which are then collected by a spectrometer along an optical fiber;

[0053] The power of the trapping laser was adjusted to a range of 0.138–0.304 W, while the power of the Raman detection laser was kept constant to a range of 1.06–3.95 mW. The Raman spectra of the particles were recorded at different trapping laser powers.

[0054] To perform force analysis on the captured particles, this embodiment quantifies the maximum velocity at which the particles escape from the optical trap based on the above experimental steps, such as... Figure 2 As shown. The formula for Stokes' drag method is as follows: F = 3πdηV. In the above formula, d is the diameter of the particle, η is the viscosity of the solution, and V is the maximum velocity at which the particle escapes from the optical trap. Therefore, the drag force of the liquid on the particle can be calculated based on the maximum velocity at which the particle escapes from the optical trap. It is important to emphasize that the calculated drag force is equal to the optical force.

[0055] To investigate the thermal effects of trapped particles, this invention quantifies the temperature rise of PS particles using Raman spectroscopy based on the aforementioned experimental steps. Raman spectroscopy characterizes sample temperature based on the temperature dependence of the inherent properties of material Raman characteristic peaks (intensity ratio, full width at half maximum, and Raman shift), offering advantages such as non-contact, non-invasiveness, and high spatial resolution measurement.

[0056] This embodiment first obtains the Raman signal of the captured PS particles, such as... Figure 3 As shown, this proves the feasibility of the thermal measurement method in this invention.

[0057] This invention employs a temperature characterization method based on Raman shift, primarily including calibration experiments and power experiments to obtain the relationship between temperature shift and power shift, respectively. Through these relationships, the power-temperature relationship of the trapped particles can be obtained after eliminating the Raman shift variable. Figure 4 As shown in Figure a, after linear fitting of the experimental data, the power-displacement coefficient of the captured particle is -1.153 cm. -1 ·W -1 By combining the temperature-displacement coefficients obtained from the calibration experiment and then performing zero-point alignment, the power-temperature relationship of the captured particles can be obtained. For example... Figure 4 As shown in Figure b, the power-temperature coefficient of the captured particles is 208 K·W. -1 .

[0058] In optical tweezers, the optical force is directly proportional to the trapping laser power. Based on the thermodynamic results measured in this embodiment, it can be observed that the optical force first increases and then decreases with increasing trapping laser power. These results indicate that the thermal effect induced by the laser is detrimental to particle trapping, and that there exists an optimal trapping power (applying the maximum optical force to the particle). In conclusion, these results are of great significance for the stable manipulation of optical tweezers.

[0059] Example 3

[0060] A particle thermodynamic measurement method based on dual-laser confocal microscopy includes the following steps:

[0061] 1. Prepare a dispersion of PE (polyethylene) particles at a concentration of 0.05-0.2 mg / ml and place it in a quartz glass container. The particle size of the PE particles is 0.1-5 μm.

[0062] 2. A 1064 nm continuous laser is focused onto the inner surface of the bottom of the quartz glass through the first objective lens to form a large light field gradient, which can capture PE particles; a CMOS camera monitors the real-time movement of the particles through the first objective lens.

[0063] The movement of a quartz dish containing PE solution is controlled by moving a precision displacement stage until the particles escape the control of the optical trap. Based on this method, the maximum escape velocity (0.138-0.304 W) can be obtained at different trapping laser powers.

[0064] 3. A 532 nm continuous laser is focused onto the captured PE particles through a second objective lens to excite their Raman signals, which are then collected by a spectrometer along an optical fiber;

[0065] The power of the trapping laser was adjusted to a range of 0.138–0.304 W, while the power of the Raman detection laser was kept constant to a range of 1.06–3.95 mW. The Raman spectra of the particles were recorded at different trapping laser powers.

[0066] To perform force analysis on the captured particles, this embodiment quantifies the maximum velocity at which the particles escape from the optical trap based on the experimental steps described above. The Stokes drag method formula is as follows: F = 3πdηV. In the above formula, d is the diameter of the particle, η is the viscosity of the solution, and V is the maximum velocity at which the particle escapes from the optical trap. Therefore, the drag force of the liquid on the particle can be calculated based on the maximum velocity at which the particle escapes from the optical trap. It is important to emphasize that the calculated drag force is equal to the optical force.

[0067] To investigate the thermal effects of trapped particles, this invention quantifies the temperature rise of PE particles using Raman spectroscopy based on the aforementioned experimental steps. Raman spectroscopy characterizes sample temperature based on the temperature dependence of the inherent properties of material Raman characteristic peaks (intensity ratio, full width at half maximum, and Raman shift), offering advantages such as non-contact, non-invasiveness, and high spatial resolution measurement.

[0068] In this embodiment, the Raman signal of the captured PE particles was first obtained, such as... Figure 5 As shown in Figure a, this demonstrates the feasibility of the thermal measurement method in this invention. By analyzing the changes in the Raman characteristic peaks, the power-displacement coefficient of the captured PE particles is -0.66 cm⁻¹. -1 ·W -1 ,like Figure 5 As shown in b, since the center displacement of the Raman characteristic peak of PE material gradually red-shifts with temperature, the negatively correlated power-displacement coefficient here initially reflects the gradually increasing temperature rise of the trapped particles.

[0069] In optical tweezers, the optical force is directly proportional to the trapping laser power. Based on the thermodynamic results measured in this embodiment, it can be observed that the optical force first increases and then decreases with increasing trapping laser power. These results indicate that the thermal effect induced by the laser is detrimental to particle trapping, and that there exists an optimal trapping power (applying the maximum optical force to the particle). In conclusion, these results are of great significance for the stable manipulation of optical tweezers.

[0070] Example 4

[0071] A particle thermodynamic measurement method based on dual-laser confocal microscopy includes the following steps:

[0072] 1. Prepare a dispersion of biological DNA at a concentration of 200 mM and place it in a quartz glass container;

[0073] 2. A 1064 nm continuous laser is focused onto the inner surface of the bottom of the quartz glass through the first objective lens to form a large light field gradient, which can capture biological DNA; a CMOS camera monitors the real-time movement of the biological DNA through the first objective lens.

[0074] The movement of a quartz dish containing biological DNA is controlled by moving a precision displacement stage until the biological DNA escapes the control of the optical trap. Based on this method, the maximum escape velocity (0.138-0.304 W) can be obtained at different trapping laser powers.

[0075] 3. A 532 nm continuous laser is used to focus onto the captured biological DNA through a second objective lens to excite their Raman signals, which are then collected by a spectrometer along an optical fiber;

[0076] The power of the capture laser was adjusted to a range of 0.138–0.304 W, while the power of the Raman detection laser was kept constant to a range of 1.06–3.95 mW. The Raman spectra of biological DNA under different capture laser powers were recorded.

[0077] To perform force analysis on the captured biological DNA, this embodiment quantifies the maximum velocity at which the biological DNA escapes from the optical trap based on the experimental steps described above. The Stokes drag method formula is as follows: F = 3πdηV. In the above formula, d is the diameter of the biological DNA, η is the viscosity of the solution, and V is the maximum velocity at which the biological DNA escapes from the optical trap. Therefore, the drag force exerted by the liquid on the biological DNA can be calculated based on the maximum velocity at which the biological DNA escapes from the optical trap. It is important to emphasize that the calculated drag force is equal to the optical force.

[0078] To investigate the thermal effects of captured biological DNA, this invention quantifies the temperature rise of biological DNA using Raman spectroscopy based on the aforementioned experimental steps. Raman spectroscopy characterizes sample temperature based on the temperature dependence of the inherent properties of material Raman characteristic peaks (intensity ratio, full width at half maximum, and Raman shift), offering advantages such as non-contact, non-invasiveness, and high spatial resolution measurement.

[0079] This embodiment first obtains the Raman signal of the captured biological DNA, such as... Figure 6 As shown in Figure a, this demonstrates the feasibility of the thermal measurement method in this invention. By analyzing the changes in Raman characteristic peaks, the power-shift coefficient of the captured biological DNA was found to be -3.87 cm⁻¹. -1 ·W -1 ,like Figure 6 As shown in b, since the center shift of the Raman characteristic peak of biological DNA gradually redshifts with temperature, the negatively correlated power-shift coefficient here initially reflects the gradual increase in temperature of the captured biological DNA.

[0080] Example 5

[0081] A particle thermodynamic measurement method based on dual-laser confocal microscopy includes the following steps:

[0082] 1. Purchase a sheep red blood cell solution with a concentration of 1%-5% (product number: SBJ-RBC-S001) and store it in a quartz glass container. The red blood cell particle size should be 6-10 μm.

[0083] 2. A 1064 nm continuous laser is focused onto the inner surface of the bottom of the quartz glass through the first objective lens to form a large light field gradient, which can capture red blood cells; a CMOS camera monitors the real-time movement of red blood cells through the first objective lens.

[0084] The movement of a quartz dish containing a red blood cell solution is controlled by moving a precision displacement stage until the red blood cells escape the control of the optical trap. Based on this method, the maximum escape velocity (0.138-0.304 W) can be obtained at different trap laser powers.

[0085] 3. A 532 nm continuous laser is focused onto the captured red blood cells through a second objective lens to excite their Raman signals, which are then collected by a spectrometer along an optical fiber;

[0086] The power of the capture laser was adjusted to a range of 0.138–0.304 W, while the power of the Raman detection laser was kept constant to a range of 1.06–3.95 mW. The Raman spectra of red blood cells under different capture laser powers were recorded.

[0087] To analyze the forces acting on the captured red blood cells, this embodiment quantifies the maximum velocity at which the red blood cells escape from the optical trap based on the experimental steps described above. The Stokes drag method formula is as follows: F = 3πdηV. In the above formula, d is the diameter of the red blood cell, η is the viscosity of the solution, and V is the maximum velocity at which the red blood cell escapes from the optical trap. Therefore, the drag force of the liquid on the particle can be calculated based on the maximum velocity at which the red blood cell escapes from the optical trap. It is important to emphasize that the calculated drag force is equal to the optical force.

[0088] To investigate the thermal effects of captured red blood cells, this invention quantifies the temperature rise of red blood cells using Raman spectroscopy based on the aforementioned experimental steps. Raman spectroscopy characterizes the temperature of a sample based on the temperature dependence of the inherent properties of the material's Raman characteristic peaks (intensity ratio, full width at half maximum, and Raman shift), offering advantages such as non-contact, non-invasiveness, and high spatial resolution measurement.

[0089] This embodiment first obtains the Raman signal of the captured red blood cells. By analyzing the changes in the Raman characteristic peaks, the power-displacement coefficient of the captured red blood cells can be obtained. Combined with the temperature-displacement coefficient obtained in the calibration experiment, the power-temperature coefficient of the red blood cells can be obtained.

[0090] In optical tweezers, the optical force is directly proportional to the capturing laser power. Based on the thermodynamic results measured in this embodiment, it can be found that while the optical force increases with increasing capturing laser power, the resulting thermal effect severely impacts cell viability. These results indicate that the laser-induced thermal effect is detrimental to the capture of biological cells and also affects their viability. In conclusion, these results are of great significance for the application of optical tweezers in the biological field.

[0091] Example 6

[0092] A particle thermodynamic measurement method based on dual-laser confocal microscopy includes the following steps:

[0093] 1. Prepare a dispersion of 0.05-0.1 mg / ml gold SAM (gold particle-modified self-assembled monolayer) and place it in a quartz glass container. The particle size of the gold particles is 0.06-0.1 μm.

[0094] 2. A 1064 nm continuous laser is focused onto the inner surface of the bottom of the quartz glass through the first objective lens to form a large light field gradient, which can capture gold SAM particles; the CMOS camera is replaced with a high-speed camera, which monitors the real-time movement of the particles through the first objective lens;

[0095] 3. A 532 nm continuous laser is focused onto the captured gold SAM particles through a second objective lens to excite their Raman signals, which are then collected by a spectrometer along an optical fiber;

[0096] The power of the trapping laser was adjusted to a range of 0.138–0.304 W, while the power of the Raman detection laser was kept constant to a range of 1.06–3.95 mW. The Raman spectra of the particles were recorded at different trapping laser powers.

[0097] In order to perform force analysis on the captured particles, this embodiment calculates the power spectrum of the displacement based on the tiny vibration displacement of the particles observed in the high-speed camera, and then obtains the optical capture stiffness and optical force of the particles.

[0098] To investigate the thermal effects of trapped particles, this invention quantifies the temperature rise of gold SAM particles using Raman spectroscopy based on the aforementioned experimental steps. Raman spectroscopy characterizes sample temperature based on the temperature dependence of the inherent properties of material Raman characteristic peaks (intensity ratio, full width at half maximum, and Raman shift), offering advantages such as non-contact, non-invasiveness, and high spatial resolution measurement.

[0099] This embodiment first obtains the Raman signal of the captured gold SAM particles. By analyzing the changes in the Raman characteristic peaks, the power-displacement coefficient of the captured gold SAM particles can be obtained. Combined with the temperature-displacement coefficient obtained in the calibration experiment, the power-temperature coefficient of the gold SAM particles can be obtained.

[0100] In optical tweezers, the optical force is directly proportional to the trapping laser power. Based on the thermodynamic results measured in this embodiment, it can be observed that the optical force first increases and then decreases with increasing trapping laser power. These results indicate that the thermal effect induced by the laser is detrimental to particle trapping, and that there exists an optimal trapping power (applying the maximum optical force to the particle). In conclusion, these results are of great significance for the stable manipulation of optical tweezers.

[0101] The above description is merely a preferred embodiment of the present invention, and should not be construed as limiting the scope of the invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A particle thermodynamic measurement method based on dual-laser confocal microscopy, characterized in that, Prepare a solution containing particles and pour the solution into a transparent container; A high-power continuous laser is focused onto the surface at the bottom of the container to capture particles. During the capture process, the real-time movement of the particles is monitored, and the velocity of the particles escaping the trap is obtained based on the particle's trajectory. Then, the optical force of the particles is obtained based on the Stokes drag method. A low-power continuous laser is focused onto the captured particles to excite Raman signals, and Raman spectroscopy is used to quantify the temperature of the particles; thus, particle thermal measurement is performed. The wavelength of high-power continuous laser is 1064 nm, and the power is 0.138-0.304 W; The low-power continuous laser has a wavelength of 532 nm and a power of 1.06-3.95 mW.

2. The particle thermodynamic measurement method based on dual-laser confocal microscopy as described in claim 1, characterized in that, The particles have a refractive index greater than that of the surrounding medium and exhibit Raman signals; the particle size is micro-nano.

3. The particle thermodynamic measurement method based on dual-laser confocal microscopy as described in claim 1, characterized in that, The particles can be microplastic particles, DNA molecules, or biological cells.

4. The particle thermodynamic measurement method based on dual-laser confocal microscopy as described in claim 1, characterized in that, Based on the particle's motion trajectory, the Stokes drag method is used to analyze the force situation of the particle.

5. The particle thermodynamic measurement method based on dual-laser confocal microscopy as described in claim 1, characterized in that, High-power continuous laser and low-power laser are in a confocal state.

6. A particle thermodynamic measurement device based on dual-laser confocal microscopy, characterized in that, The method for implementing any one of claims 1-5 includes a Raman capture unit and a Raman detection unit, wherein the capture unit includes a high-power continuous laser and a high-speed camera, and the Raman detection unit includes a low-power continuous laser and a Raman spectrometer, wherein the lasers emitted by the high-power continuous laser and the low-power continuous laser are in a confocal state when in use.

7. The particle thermodynamic measurement device based on dual-laser confocal microscopy technology according to claim 6, characterized in that, A filter is added at the exit of the low-power continuous laser.

Images