阅读说明：本技术 基于上转换发光全内反射单颗粒成像装置以及成像方法 (Single-particle imaging device and method based on up-conversion luminescence total internal reflection ) 是由 陈红旗 夏婉莹 于 2019-10-10 设计创作，主要内容包括：本发明公开了一种基于上转换发光全内反射单颗粒成像装置以及成像方法,包括：近红外半导体激光器、三维可调准直扩束镜、激发滤光片、二色镜、物镜、载物台、发射滤光片、相机、光路；近红外半导体激光器与三维可调准直扩束镜相连接,三维可调准直扩束镜与光路相连通且两者之间设置有激发滤光片；光路内的通道的中部设置有二色镜,二色镜面向激发滤光片；光路的顶部由下至上依次设置有物镜、载物台,载物台上设置有样品器皿,样品器皿内盛有稀土掺杂的上转换发光纳米材料；光路内的通道的下部设置有发射滤光片,相机位于光路的下端的下方。该成像方法具有穿透性好、对生物样品损害小、信噪比高,灵敏度高,成像速度快等特点。(The invention discloses a single-particle imaging device and an imaging method based on up-conversion luminescence total internal reflection, which comprises the following steps: the device comprises a near-infrared semiconductor laser, a three-dimensional adjustable collimation and beam expansion lens, an excitation optical filter, a dichroic mirror, an objective lens, an objective table, an emission optical filter, a camera and an optical path; the near-infrared semiconductor laser is connected with a three-dimensional adjustable collimation and beam expansion lens, the three-dimensional adjustable collimation and beam expansion lens is communicated with the light path, and an excitation filter is arranged between the three-dimensional adjustable collimation and beam expansion lens and the light path; a dichroic mirror is arranged in the middle of the channel in the light path and faces the excitation optical filter; the top of the light path is sequentially provided with an objective lens and an objective table from bottom to top, a sample vessel is arranged on the objective table, and the sample vessel is filled with the rare earth doped up-conversion luminescent nano material; an emission filter is arranged at the lower part of the channel in the light path, and the camera is positioned below the lower end of the light path. The imaging method has the characteristics of good penetrability, small damage to the biological sample, high signal-to-noise ratio, high sensitivity, high imaging speed and the like.)

1. A single particle imaging device based on upconversion luminescent total internal reflection, comprising: the device comprises a near-infrared semiconductor laser (1), a three-dimensional adjustable collimation and expansion lens (2), an excitation optical filter (3), a dichroic mirror (4), an objective lens (5), an objective table (6), an emission optical filter (7), a camera (8) and an optical path (10); the near-infrared semiconductor laser (1) is connected with a three-dimensional adjustable collimation and beam expansion lens (2), the three-dimensional adjustable collimation and beam expansion lens (2) is communicated with a light path (10), and an excitation filter (3) is arranged between the three-dimensional adjustable collimation and beam expansion lens and the light path; a dichroic mirror (4) is arranged in the middle of a channel in the light path (10), and the dichroic mirror (4) faces the excitation filter (3); an objective lens (5) and an objective table (6) are sequentially arranged at one end of the optical path (10) from inside to outside, a sample vessel (9) is arranged on the objective table (6), and the rare earth doped up-conversion luminescent nano material is contained in the sample vessel (9); an emission filter (7) is arranged in a channel in the other end of the light path (10), and the camera (8) faces the tail of the other end of the light path (10).

2. The upconversion luminescence-based total internal reflection single particle imaging device according to claim 1, wherein the excitation light source emitted by the near-infrared semiconductor laser (1) has a wavelength of at least one of 808nm, 980nm, 1064 nm.

3. The up-conversion luminescence-based total internal reflection single particle imaging device according to claim 1, wherein the excitation filter (3) is selected from a narrow band-pass filter;

preferably, the dichroic mirror (4) is a long, reverse and short pass dichroic mirror;

more preferably, the objective lens (5) is a total internal reflection objective lens with the trade mark of N.A. ═ 1.49;

further preferably, the camera (8) is a photosetrics Prime95B backside illuminated sCMOS camera.

4. The upconversion luminescent-based total internal reflection single particle imaging apparatus according to any one of claims 1 to 3, wherein the camera (8) is connected to a computer.

5. The upconversion luminescent-based total internal reflection single particle imaging device according to any one of claims 1 to 3, wherein the rare earth doped upconversion luminescent nanomaterial is NaYF₄:Yb,[email protected]₄Upconversion nanoparticles, NaGdF₄:Yb,[email protected]₄Upconversion nanoparticles and NaYF₄:Yb,[email protected]₄Up-converting at least one of the nanoparticles.

6. The upconversion luminescent total internal reflection based single particle imaging device according to any one of claims 1 to 3, wherein the sample vessel (9) is a glass-bottom culture vessel or a silanized glass slide.

7. The up-conversion luminescence-based total internal reflection single particle imaging device according to claim 6, wherein, when the sample vessel (9) is a glass-bottom culture vessel, the focal length is 2200 and 2300 nm;

or, when the sample vessel (9) is a silanized glass sheet, the focal length is 3700-3800 nm.

8. The upconversion luminescent-based total internal reflection single particle imaging device according to claim 6, wherein the near-infrared semiconductor laser (1) and the three-dimensional adjustable collimating and beam expanding lens (2) are connected through an FC standard interface.

9. A method for imaging single particle based on upconversion luminescence total internal reflection, wherein the method is performed in the device according to any one of claims 1 to 8, and comprises:

1) placing a rare earth doped up-conversion luminescent nano material in a sample vessel (9), then starting a near-infrared semiconductor laser (1) to emit an excitation light source to enter a three-dimensional adjustable collimation and beam expansion lens (2), wherein the three-dimensional adjustable collimation and beam expansion lens (2) can collimate, expand and excite the excitation light;

2) the exciting light passes through the exciting light filter (3) to remove stray light, and the purified exciting light is reflected by the dichroic mirror (4) and enters the objective lens (5); adjusting the incidence angle of the exciting light through the three-dimensional adjustable collimation and expansion lens (2) so that the exciting light forms a critical angle that the light beam in the horizontal direction is close to disappear;

3) after the excitation light excites the rare earth doped up-conversion luminescent nano material, the up-conversion luminescent nano material generates emission light, the emission light is collected by an objective lens (5), reflected by a dichroic mirror (4) and passes through an emission optical filter (7) to filter out the excitation light and other stray light, and the emission light after the emission optical filter (7) is collected by a camera (8) to obtain total internal reflection imaging.

Technical Field

The invention relates to total internal reflection imaging, in particular to a single-particle imaging device and an imaging method based on up-conversion luminescence total internal reflection.

Background

The total internal reflection imaging technology adopts an evanescent wave (evanescent field) as an excitation light source of a sample, has shallow excitation depth, effectively controls the excitation volume and interference of incident light, and has the characteristics of high signal-to-noise ratio, high resolution and the like. In the past decade, the method is widely applied to the fields of monomolecular imaging, biomacromolecule interaction, biomacromolecule conformation change, monomolecular electron transfer, ATPase turnover, single molecule structure change in polymers, single particle tracing and the like in living cells. At present, the total internal reflection imaging technology adopts common fluorescence emission modes (short wave excitation and long wave emission), the related processes are single photon processes, the wavelength of the used excitation light is generally in a visible light region (such as 405nm,488nm,533nm and 632nm), the biological tissue is easily subjected to light damage, and the tissue penetrating power is poor; the adopted fluorescent materials mainly comprise organic dyes, quantum dots and the like, and the materials generally have the defects of serious photobleaching property, photoflickering (Blinking), high toxicity and the like.

Disclosure of Invention

The invention aims to provide a single-particle imaging device based on upconversion luminescence total internal reflection and an imaging method.

In order to achieve the above object, the present invention provides a single particle imaging device based on up-conversion luminescence total internal reflection, comprising: the device comprises a near-infrared semiconductor laser, a three-dimensional adjustable collimation and beam expansion lens, an excitation optical filter, a dichroic mirror, an objective lens, an objective table, an emission optical filter, a camera and an optical path; the near-infrared semiconductor laser is connected with a three-dimensional adjustable collimation and beam expansion lens, the three-dimensional adjustable collimation and beam expansion lens is communicated with the light path, and an excitation filter is arranged between the three-dimensional adjustable collimation and beam expansion lens and the light path; a dichroic mirror is arranged in the middle of the channel in the light path and faces the excitation optical filter; an objective lens and an objective table are sequentially arranged at one end of the light path from inside to outside, a sample vessel is arranged on the objective table, and the sample vessel is filled with the rare earth doped up-conversion luminescent nano material; an emission filter is arranged in the channel at the other end of the channel in the light path, and the camera faces the tail of the other end of the light path.

Preferably, the wavelength of the excitation light source emitted by the near-infrared semiconductor laser is at least one of 808nm, 980nm and 1064 nm.

Preferably, the excitation filter is a narrow band pass filter;

preferably, the dichroic mirror is a long-reflective short-pass dichroic mirror;

more preferably, the objective lens is a total internal reflection objective lens with the trade mark of n.a. ═ 1.49;

further preferably, the camera is a photosetrics Prime95B backside illuminated sCMOS camera.

Preferably, the camera is connected to a computer.

Preferably, the rare earth doped up-conversion luminescent nano material is NaYF₄:Yb,[email protected]₄Upconversion nanoparticles, NaGdF₄:Yb,[email protected]₄Upconversion nanoparticles and NaYF₄:Yb,[email protected]₄Up-converting at least one of the nanoparticles.

Preferably, the sample vessel is a glass-bottomed petri dish or a silanized glass slide.

Preferably, when the sample vessel is a glass bottom culture vessel, the focal length is 2200-;

or, when the sample vessel is a silanized glass sheet, the focal length is 3700-3800 nm.

Preferably, the near-infrared semiconductor laser and the three-dimensional adjustable collimation and beam expansion lens are connected through an FC standard interface.

The invention also provides an up-conversion luminescence-based total internal reflection single particle imaging method, which is performed in the up-conversion luminescence-based total internal reflection single particle imaging device, and comprises the following steps:

1) placing the rare earth doped up-conversion luminescent nano material in a sample vessel, then starting a near-infrared semiconductor laser to emit an excitation light source to enter a three-dimensional adjustable collimation beam expanding lens, wherein the three-dimensional adjustable collimation beam expanding lens can collimate the excitation light after beam expansion;

2) exciting light passes through an excitation filter to remove stray light, and the purified exciting light is reflected by a dichroic mirror and enters an objective lens; adjusting the incidence angle of exciting light through a three-dimensional adjustable collimation beam expanding lens so that the exciting light forms a critical angle that the light beam in the horizontal direction is close to disappear;

3) after the excitation light excites the rare earth doped up-conversion luminescent nano material, the up-conversion luminescent nano material generates emission light, the emission light is collected by the objective lens and reflected by the dichromatic mirror, and passes through the emission filter to filter out the excitation light and other stray light, and the camera collects the emission light after the emission filter to obtain total internal reflection imaging.

In the technical scheme, a set of imaging device based on up-conversion luminescence total internal reflection is built; a single particle imaging method based on up-conversion luminescence total internal reflection is established. The rare earth doped up-conversion luminescent nano material is a unique nano material, absorbs the energy of a plurality of photons through a multi-photon mechanism, jumps to a higher energy level, and emits light with higher energy (compared with incident light) through energy conversion, so that the emitted light is shorter than an excitation light wave (long-wave excitation and short-wave emission). The device utilizes a near-infrared semiconductor laser (such as near-infrared light of 808nm, 980nm, 1064nm and the like) as an excitation light source, takes a rare earth doped up-conversion luminescent nano material as a luminescent object, combines a total internal reflection special objective lens, adopts a high-speed and high-sensitivity sCMOS camera as a photographing camera, realizes total internal reflection by adjusting the incident angle of laser, generates evanescent waves, and realizes total internal reflection imaging based on up-conversion luminescent. The method organically combines the up-conversion luminescent nano material and the total internal reflection imaging, can realize the total internal reflection single-particle imaging based on long-wave excitation and short-wave emission, and is applied to the field of single-particle detection; the method has the characteristics of good penetrability of the biological sample, small damage, high signal-to-noise ratio, high sensitivity, high imaging speed and the like. Meanwhile, the method has photobleaching resistance and no 'blisking' phenomenon.

Additional features and advantages of the invention will be set forth in the detailed description which follows.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention and not to limit the invention. In the drawings:

FIG. 1 is a diagram of a single particle imaging device based on up-conversion luminescence total internal reflection

FIG. 2 shows NaYF in the detection example₄:Yb,[email protected]₄The luminescence spectrum and transmission electron micrograph of the up-conversion nanometer material (part A is a fluorescence spectrum picture, part B is a transmission electron micrograph);

FIG. 3 is a view of a light beam observed during image formation in example 1;

FIG. 4 is a graph showing the result of imaging of the sample in test example 1;

FIG. 5 is a graph showing the result of imaging of the sample in test example 2.

Description of the reference numerals

1. Near-infrared semiconductor laser 2 and three-dimensional adjustable collimation beam expanding lens

3. Excitation filter 4, dichroic mirror

5. Objective lens 6 and stage

7. Emission filter 8 and camera

9. Sample vessel 10, light path

Detailed Description

The following detailed description of embodiments of the invention refers to the accompanying drawings. It should be understood that the detailed description and specific examples, while indicating the present invention, are given by way of illustration and explanation only, not limitation.

In the present invention, unless otherwise specified, the directional words "upper, lower, inner, outer" and the like included in the terms merely represent the orientation of the terms in a conventional use state or are colloquially understood by those skilled in the art, and should not be construed as limiting the terms.

The invention provides a single-particle imaging device based on up-conversion luminescence total internal reflection, as shown in figure 1, comprising: the device comprises a near-infrared semiconductor laser 1, a three-dimensional adjustable collimation beam expander 2, an excitation optical filter 3, a dichroic mirror 4, an objective lens 5, an objective table 6, an emission optical filter 7, a camera 8 and an optical path 10; the near-infrared semiconductor laser 1 is connected with a three-dimensional adjustable collimation and expansion lens 2, the three-dimensional adjustable collimation and expansion lens 2 is communicated with a light path 10, and an excitation filter 3 is arranged between the three-dimensional adjustable collimation and expansion lens 2 and the light path 10; a dichroic mirror 4 is arranged in the middle of the channel in the light path 10, and the dichroic mirror 4 faces the excitation filter 3; an objective lens 5 and an objective table 6 are sequentially arranged at one end of a light path 10 from inside to outside, a sample vessel 9 is arranged on the objective table 6, and the rare earth doped up-conversion luminescent nano material is contained in the sample vessel 9; an emission filter 7 is disposed in a channel in the other end of the optical path 10, and a camera 8 faces the tail of the other end of the optical path 10.

In the present invention, the wavelength of the excitation light source may be selected within a wide range, but in order to further improve the imaging effect, it is preferable that the wavelength of the excitation light source emitted by the near-infrared semiconductor laser 1 is at least one of 808nm, 980nm, 1064 nm.

In the present invention, the excitation power of the excitation light source may be selected within a wide range, but in order to further improve the imaging effect, the excitation power of the near-infrared semiconductor laser 1 is selected from at least one of 200mw, 600mw, and 1000 mw.

In the present invention, the type of the excitation filter 3 can be selected within a wide range, but in order to further improve the imaging effect, it is preferable to select a narrow band-pass filter for the excitation filter 3.

In the present invention, the type of the dichroic mirror 4 can be selected within a wide range, but in order to further improve the imaging effect, it is preferable that the dichroic mirror 4 is a long-reverse short-pass dichroic mirror.

In the present invention, the type of the objective lens 5 can be selected in a wide range, but in order to further enhance the imaging effect, it is preferable that the objective lens 5 is a total internal reflection exclusive objective lens of the brand n.a. ═ 1.49.

In the present invention, the type of the camera 8 can be selected within a wide range, but in order to further enhance the sensitivity of the camera 8 to improve the imaging effect, it is preferable that the camera 8 is a cmos camera of a backside illuminated type under the trade name Photometrics Prime 95B.

In the above embodiment, in order to further facilitate the processing of data, the camera 8 is preferably connected to a computer.

In the present invention, the specific kind of the rare earth doped upconversion luminescent nanomaterial can be selected from a wide range, but in order to further improve the imaging effect, it is preferable that the rare earth doped upconversion luminescent nanomaterial is NaYF₄:Yb,[email protected]₄Upconversion nanoparticles, NaGdF₄:Yb,[email protected]₄Upconversion nanoparticles and NaYF₄:Yb,[email protected]₄Up-converting at least one of the nanoparticles.

In the above embodiment, the specific kind of the sample vessel 9 may be selected within a wide range, but for further convenience of handling, it is preferable that the sample vessel 9 is a glass-bottom culture vessel or a silanized glass slide.

In the above embodiment, for different types of sample vessels 9, in order to further improve the imaging effect, it is preferable that the focal length is 2200-; alternatively, where the sample vessel 9 is a silanized glass slide, the focal length is 3700-3800 nm.

In the present invention, in order to further improve the transmission effect of the excitation light between the near-infrared semiconductor laser 1 and the three-dimensional adjustable collimation and expansion lens 2, preferably, the near-infrared semiconductor laser 1 and the three-dimensional adjustable collimation and expansion lens 2 are connected by an FC standard interface.

The invention also provides an up-conversion luminescence-based total internal reflection single particle imaging method, which is performed in the up-conversion luminescence-based total internal reflection single particle imaging device, and comprises the following steps:

1) placing the rare earth doped up-conversion luminescent nano material in a sample vessel 9, then starting a near-infrared semiconductor laser 1 to emit an excitation light source to enter a three-dimensional adjustable collimation and expansion lens 2, wherein the three-dimensional adjustable collimation and expansion lens 2 can collimate the excitation light after beam expansion;

2) exciting light passes through an excitation filter 3 to remove stray light, and the purified exciting light is reflected by a dichroic mirror 4 to enter an objective lens 5; adjusting the incidence angle of the exciting light through the three-dimensional adjustable collimation beam expanding lens 2 so that the exciting light forms a critical angle that the light beam in the horizontal direction is close to disappear;

3) after the excitation light excites the rare earth doped up-conversion luminescent nano material, the up-conversion luminescent nano material generates emission light, the emission light is collected by an objective lens (5), reflected by a dichroic mirror (4) and passes through an emission filter 7 to filter out the excitation light and other stray light, and a camera 8 collects the emission light after the emission filter 7 to obtain total internal reflection imaging.

The present invention is further illustrated by the following examples. NaYF in the following examples₄:Yb,[email protected]₄Up-converted nanoparticles were prepared by the reference co-precipitation method (reference Wang H, Lu Y, Wang L, Chen H (2019) Detection of type amine and type activity using red region emission NaGdF4: Yb, Er NaYF4up conversion nanoparticles. Talanta 197:558-566.doi:10.1016/j. talanta.2019.01.079).

Preparation example 1

Silanization treatment of glass sheet:

and selecting a glass sheet with the specification of 24 x 50 mm for silanization treatment. First, the glass sheet was subjected to an ultrasonic cleaning treatment with a household detergent three times for 10 minutes each. Subsequently, the glass sheet was subjected to ultrasonic cleaning treatment with ultrapure water, and similarly, the treatment was carried out three times for 10 minutes each. The glass sheet was then oven dried. And then carrying out hydroxylation treatment on the dried glass sheet. Soaking the glass sheets in piranha solution (a mixture of concentrated sulfuric acid and 30% hydrogen peroxide in a weight ratio of 7:3), and heating at 80 deg.C for 2 hr until no bubbles are generated. And then ultrasonically washing the glass sheet by using deionized water, treating twice for 15 minutes each time, and drying the glass sheet by using an oven. And then performing silanization treatment on the glass sheet, namely soaking the glass sheet by using a mixed solution (weight ratio is 1:1000) of 3-Aminopropyltriethoxysilane (APTES) and absolute ethyl alcohol, slowly shaking for 1 hour at 25 ℃, and then cleaning the glass sheet by using ethyl alcohol. And finally, drying by using an oven.