A fluorescent quantum dot detection optical system
By designing a fluorescent quantum dot detection optical system, employing a dichroic mirror and objective lens, and combining collimation and homogenization components, the fluorescence collection optical path was optimized, thereby improving the uniformity of excitation light and the efficiency of fluorescence collection. This solved the problems existing in traditional optical systems and improved imaging accuracy and stability.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- XUZHOU NORMAL UNIVERSITY
- Filing Date
- 2025-08-04
- Publication Date
- 2026-07-14
AI Technical Summary
Traditional optical systems suffer from problems such as insufficient excitation light uniformity, low fluorescence collection efficiency, and low multi-band switching accuracy in fluorescence quantum dot detection, which affect imaging accuracy and stability.
Design an optical system for detecting fluorescent quantum dots. The system employs a dichroic mirror and objective lens, combined with an excitation light module, a fluorescence collection module, and an imaging optical path module. The excitation light uniformity is achieved through collimation and homogenization components, the fluorescence collection optical path is optimized, and multi-band automated switching is realized through a filter group and a stepper motor.
It improves the uniformity of excitation light, enhances fluorescence collection efficiency and spectral selectivity, reduces stray light interference, and improves imaging accuracy and stability.
Smart Images
Figure CN224500396U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of optical microscopy imaging technology, and relates to the integration of laser optical path, fluorescence collection and imaging system for fluorescent quantum dot detection, specifically to a fluorescent quantum dot detection optical system. Background Technology
[0002] Fluorescent quantum dot detection utilizes the unique optical properties of quantum dots to achieve highly sensitive analysis. Its luminescence mechanism involves the quantum dot being stimulated by light or electricity, causing electrons to transition to an excited state, and releasing fluorescence of a specific wavelength upon returning to the ground state. However, this technology relies on optical systems in practical applications, and traditional optical systems have significant limitations, such as insufficient excitation light uniformity, low fluorescence collection efficiency, stray light interference, and low accuracy in multi-band switching. A detailed analysis follows:
[0003] Insufficient excitation light uniformity: Ordinary LED light sources are not collimated and homogenized, resulting in uneven distribution of excitation light intensity on the sample surface, which affects the consistency of quantum dot fluorescence signals;
[0004] Low fluorescence collection efficiency: deviations in the spectral characteristics of the dichroic mirror or optical path offsets can easily cause fluorescence signal attenuation, reducing the signal-to-noise ratio of single quantum dot detection;
[0005] Stray light interference: Reflection from optical components or system design defects can cause stray light to enter the imaging path, interfering with fluorescence signal acquisition;
[0006] Low accuracy of multi-band switching: When manually changing filters, the wavelength matching error is large, which cannot meet the detection requirements of different quantum dot excitation / emission spectra. Utility Model Content
[0007] To address the aforementioned problems, the main objective of this invention is to design a fluorescent quantum dot detection optical system that solves the issues of low laser uniformity, low fluorescence collection efficiency, and low multi-band switching accuracy, especially the problems of low imaging accuracy and stability in single-molecule tracking scenarios of nanoscale quantum dots.
[0008] To achieve the above objectives, the present invention adopts the following technical solution:
[0009] A fluorescent quantum dot detection optical system generates a fluorescence image based on the fluorescence generated by the sample being detected. The optical system includes an excitation optical path and a transmission optical path. The excitation optical path includes an excitation light module that emits excitation light and reflects the excitation light to the objective lens through a dichroic mirror. The transmission optical path receives the fluorescence emitted by the objective lens based on the dichroic mirror, and a fluorescence collection module and an imaging optical path module are sequentially arranged along the emission direction of the fluorescence.
[0010] The dichroic mirror includes an incident end and a reflecting end disposed in the excitation optical path for reflecting excitation light to the objective lens, and a transmitting end and an emitting end disposed in the transmission optical path for receiving fluorescence emitted by the objective lens.
[0011] The excitation light module includes a light source and a collimation component and a homogenization component arranged sequentially along the emission direction of the light source. The excitation light emitted by the homogenization component corresponds to the incident end of the dichroic mirror, and the reflecting end and the transmitting end of the dichroic mirror correspond to the objective lens.
[0012] A fluorescence collection module is located at the emission end of a dichroic mirror and includes a filter group for filtering the fluorescence generated by the sample being detected. The filter group is configured as a three-channel emission filter.
[0013] The imaging optical path module is set in the transmission optical path of the filter group that emits fluorescence, and includes, in sequence, a tube lens that receives and scales the fluorescence image plane to the camera target surface to a suitable size, and a reducing lens.
[0014] As a further description of this utility model, the dichroic mirror is disposed at the emission end of the excitation light generated by the excitation light module and is located above the objective lens.
[0015] The fluorescence collection module is positioned above the excitation light module, and the filter group corresponds to the dichroic mirror;
[0016] The imaging optical path module is positioned above the fluorescence collection module, and the tube lens corresponds to the filter group, with the reducing lens positioned between the tube lens and the camera.
[0017] As a further description of this utility model, the dichroic mirror is configured as a total reflection dichroic mirror with an edge slope of <1%, and the incident light rays in the excitation light path and the transmission light path are at an incident angle of 45°±1° with the corresponding mirror surface.
[0018] As a further description of this utility model, the numerical aperture of the objective lens is between 0.4 and 0.8;
[0019] The tube lens is matched with the objective lens, with a focal length of 200mm and a wavefront error of <λ / 4 RMS @546nm.
[0020] As a further description of this utility model, the light source is set as an adjustable power LED lamp with a wavelength of 440nm;
[0021] The collimation assembly consists of a convex lens group and an aperture. The excitation light emitted by the light source is converted into a parallel beam by the convex lens group and the aperture in sequence.
[0022] The homogenization component is configured to work in conjunction with a compound eye lens array and an integrating mirror. The excitation light emitted by the collimation component is sequentially split by the compound eye lens array, and the integrating mirror superimposes the multiple channels.
[0023] As a further description of this utility model, the filter group is configured as a three-channel emission filter of BP655 / 20, BP565 / 20 and BP590 / 30. The filter is placed on the turntable by a pressure plate and the turntable is driven by a stepper motor to switch channels.
[0024] As a further description of this utility model, the camera has a quantum efficiency of >90% @650nm and noise <1e-.
[0025] Compared with the prior art, the technical effects of this utility model are as follows:
[0026] This invention provides an optical system for detecting fluorescent quantum dots, including a dichroic mirror and an objective lens, as well as an excitation light module, a fluorescence collection module, and an imaging light path module arranged sequentially along the optical path. The excitation light path, composed of a collimation component and a homogenization component, achieves a uniform distribution of excitation light intensity on the sample surface. The configuration of the dichroic mirror and filters in the fluorescence collection light path is optimized to improve the collection efficiency and spectral selectivity of the quantum dot fluorescence signal. Furthermore, a stepper motor enables automated switching of multi-channel filters to adapt to the spectral characteristics of different fluorescent quantum dots. Attached Figure Description
[0027] Figure 1 This is an overall structural view of the present invention;
[0028] Figure 2 This is a schematic diagram of the optical path principle of this utility model;
[0029] Figure 3 This is a structural view of the fluorescence collection module of this utility model.
[0030] In the diagram, 1. Dichroic mirror, 2. Objective lens, 3. Excitation light module, 4. Fluorescence collection module, 41. Filter, 42. Pressure plate, 43. Turntable, 44. Stepper motor, 45. Fixing box, 46. Fixing shaft, 47. Bearing, 48. Drive gear, 5. Imaging optical path module, 51. Tube lens, 52. Reducing mirror, 53. Camera, 54. Mirror, A. Object plane, B. Image plane. Detailed Implementation
[0031] The present invention will now be described in detail with reference to the accompanying drawings:
[0032] In one embodiment of this utility model, a fluorescent quantum dot detection optical system is disclosed, which generates a fluorescence image based on the fluorescence produced by the sample being detected. Specifically, the sample absorbs light energy under excitation light and emits fluorescence, which is then collected and imaged to generate a fluorescence image; for example... Figure 1-2As shown, the optical system includes a dichroic mirror 1 and an objective lens 2, as well as an excitation light module 3, a fluorescence collection module 4, and an imaging light path module 5 arranged along the optical path. The optical path in this embodiment includes an excitation light path and a transmission light path. The excitation light path includes an excitation light module 3 that emits excitation light, which reflects the excitation light to the objective lens 2 through the dichroic mirror 1. The transmission light path receives the fluorescence emitted by the objective lens 1 based on the dichroic mirror 1, and the fluorescence collection module 4 and the imaging light path module 5 are arranged sequentially along the emission direction of the fluorescence. The dichroic mirror 1 includes an incident end and a reflecting end disposed in the excitation optical path for reflecting excitation light to the objective lens 2, and a transmitting end and an emitting end disposed in the transmission optical path for receiving fluorescence emitted by the objective lens 2; the excitation light module 3 includes a light source, and a collimating component and a homogenizing component disposed sequentially along the emission direction of the light source, wherein the excitation light emitted by the homogenizing component corresponds to the incident end of the dichroic mirror 1, and the reflecting end and the transmitting end of the dichroic mirror 1 correspond to the objective lens 2; the fluorescence collection module 4 is disposed in the emitting end of the dichroic mirror 1, and includes a filter group for filtering the fluorescence generated by the detection sample, wherein the filter group is configured as a three-channel emission filter 41; the imaging optical path module 5 is disposed in the transmission optical path in which the filter group emits fluorescence, and includes a tube lens 51 and a reducing lens 52 that receive and scale the fluorescence image plane to the target surface of the camera 53 to an appropriate size.
[0033] It should be noted that in this embodiment, the arrangement of the optical path also includes the structural coordination of each component, but is not limited to this arrangement. Specifically, the dichroic mirror 1 is arranged at the emission end of the excitation light generated by the excitation light module 3 and is located above the objective lens 2; the fluorescence collection module 4 is arranged above the excitation light module 3, and the filter group corresponds to the dichroic mirror 1; the imaging optical path module 5 is arranged above the fluorescence collection module 4, and the tube lens 51 corresponds to the filter group; the reducing mirror 52 is arranged between the tube lens 51 and the camera 53.
[0034] This embodiment provides a detailed analysis of each part of the aforementioned optical system, as follows:
[0035] I. Excitation Light Module
[0036] Light source: 440nm wavelength LED lamp, adjustable power (15W), with heat dissipation structure to prevent wavelength drift caused by temperature rise;
[0037] Collimation component: Composed of a convex lens group and an aperture. The excitation light emitted by the light source is converted into a parallel beam through the convex lens group and the aperture in sequence. The divergence angle of the output beam after collimation of the excitation light emitted by the LED lamp is <1°.
[0038] Homogenization component: The compound eye lens array works in conjunction with the integrating mirror. The excitation light emitted by the collimating component is sequentially split by the compound eye lens array, and the multi-channel integrating mirror is superimposed to form a uniform excitation spot on the object plane A of objective lens 2, with a uniformity variation coefficient of <3%.
[0039] II. Fluorescence Collection Optical Path
[0040] Objective lens: Olympus UPLFLN 40X objective lens, with a numerical aperture between 0.4 and 0.8, a high numerical aperture suitable for quantum dot samples.
[0041] Dichroic mirror: DM490 type total reflection dichroic mirror, including transmission direction (transmission light path) and reflection direction (excitation path); the edge slope of dichroic mirror 1 is <1% (T80%→R80%), and the incident light rays in the excitation light path and transmission light path are at an incident angle of 45°±1° with the corresponding mirror surface to avoid signal attenuation caused by polarization effect.
[0042] Specifically, in this embodiment, an Olympus UPLFLN 40X objective lens with a numerical aperture (NA) ≥ 0.75 and a dichroic mirror in the fluorescence band of 505 nm-800 nm (Tavg) are used. a >95%, Tabs>90%), to improve fluorescence collection efficiency.
[0043] The fluorescence collection module features a filter group consisting of three emission filters 41: BP655 / 20, BP565 / 20, and BP590 / 30. The filters 41 are placed on a turntable 43 via a pressure plate 42. A stepper motor 44 drives the turntable 43 to switch channels, with a switching time of <0.5s. Specifically, for example... Figure 1 and 3 As shown, the fluorescence collection module 4 includes a fixed box 45 disposed above the dichroic mirror 1. The lower part of the fixed box 45 is hollowed out corresponding to the position of the dichroic mirror 1. A turntable 43 with gears on its outer periphery is disposed inside. A fixed shaft 46 and a bearing 47 are disposed in the middle of the turntable 43. The filter 41 is fixed above the turntable 43 by a pressure plate 42. A stepper motor 44 is located above the fixed box 45, and a drive gear 48 is disposed on the drive shaft of the stepper motor 44. The drive gear 48 drives the turntable 43 to rotate and change the filter 41.
[0044] III. Imaging Optical Path Module
[0045] Tube lens: Infinity correction design (focal length 200mm), matched with objective lens, wavefront error <λ / 4 RMS @546nm, ensuring imaging resolution;
[0046] Camera: Prime-95B-25mm scientific-grade CMOS camera, quantum efficiency >90% @650nm, noise <1e-, compatible target area is 25mm×25mm;
[0047] Reducer: Magnification 0.5×, adapts image plane B to the 25mm×25mm camera target surface.
[0048] It should be noted that, as Figure 2 As shown, in order to make the structure compact and reduce the space, a reflector 54 is set in the optical path of the tube lens 51 and the reducing mirror 52. The incident angle and reflection angle of the reflector 54 are both 45°±1° with the mirror surface.
[0049] In addition, in this embodiment, the mechanical inner walls of the above-mentioned optical elements (dichroic mirror, tube lens, reflector, and reducing mirror) are all treated with anti-stray threads and anodized black (reflectivity <2%) to eliminate stray light, and an aperture is set in the imaging optical path to block non-imaging light.
[0050] Based on the disclosed fluorescent quantum dot detection optical system, its working process includes the following steps:
[0051] Excitation light homogenization step: The light from the 440nm LED lamp passes sequentially through collimation, compound eye lens, and integrating mirror to form a uniform excitation light spot on the surface of the test sample (quantum dot chip);
[0052] Fluorescence collection steps: Quantum dots absorb excitation light to generate fluorescence, which is collected sequentially by an objective lens, passes through a dichroic mirror, and is dispersed by a filter to select the corresponding wavelength band of fluorescence for different filters;
[0053] Imaging and detection steps: The fluorescence after spectral screening passes through a tube lens and a reducing lens in sequence and is focused onto the camera to achieve multi-channel fluorescence imaging and spectral detection.
[0054] The above content discloses the fluorescent quantum dot detection optical system of this utility model. Compared with the prior art, this utility model has the following advantages:
[0055] 1. Improved excitation light uniformity: The combination of compound eye lens and integrating lens makes the excitation light uniformity CV < 3%, avoiding quantum dot signal fluctuations caused by uneven light intensity;
[0056] 2. Improved fluorescence collection efficiency: With matching dichroic mirror and objective lens, fluorescence collection efficiency >85%, and single quantum dot signal-to-noise ratio >15dB;
[0057] 3. Enhanced spectral selectivity: The three-channel filter automatically switches to adapt to quantum dots with different emission wavelengths (such as CdSe / ZnS core-shell quantum dots and Perovskite quantum dots).
[0058] 4. Effective suppression of stray light: Anodized black treatment and aperture design reduce background noise by 40%, improve the positioning accuracy of single-molecule tracking (<100nm), and effectively reduce stray light interference.
[0059] The above embodiments are only used to illustrate the technical solution of this utility model and are not intended to limit it. Any other modifications or equivalent substitutions made by those skilled in the art to the technical solution of this utility model, as long as they do not depart from the spirit and scope of the technical solution of this utility model, should be covered within the scope of the claims of this utility model.
Claims
1. A fluorescent quantum dot detection optical system, which generates a fluorescence image based on the fluorescence produced by the sample being detected, characterized in that: The optical system includes an excitation optical path and a transmission optical path; the excitation optical path includes an excitation light module that emits excitation light and reflects the excitation light to the objective lens through a dichroic mirror; The transmission optical path is based on the dichroic mirror receiving the fluorescence emitted by the objective lens, and the fluorescence collection module and the imaging optical path module are arranged sequentially along the emission direction of the fluorescence; The dichroic mirror includes an incident end and a reflecting end disposed in the excitation optical path for reflecting excitation light to the objective lens, and a transmitting end and an emitting end disposed in the transmission optical path for receiving fluorescence emitted by the objective lens. The excitation light module includes a light source and a collimation component and a homogenization component arranged sequentially along the emission direction of the light source. The excitation light emitted by the homogenization component corresponds to the incident end of the dichroic mirror, and the reflecting end and the transmitting end of the dichroic mirror correspond to the objective lens. A fluorescence collection module is located at the emission end of a dichroic mirror and includes a filter group for filtering the fluorescence generated by the sample being detected. The filter group is configured as a three-channel emission filter. The imaging optical path module is set in the transmission optical path of the filter group that emits fluorescence, and includes, in sequence, a tube lens that receives and scales the fluorescence image plane to the camera target surface to a suitable size, and a reducing lens.
2. The fluorescent quantum dot detection optical system according to claim 1, characterized in that: The dichroic mirror is positioned at the emission end of the excitation light generated by the excitation light module and is located above the objective lens; The fluorescence collection module is positioned above the excitation light module, and the filter group corresponds to the dichroic mirror; The imaging optical path module is positioned above the fluorescence collection module, and the tube lens corresponds to the filter group, with the reducing lens positioned between the tube lens and the camera.
3. The fluorescent quantum dot detection optical system according to claim 1, characterized in that: The dichroic mirror is set as a total reflection dichroic mirror with an edge slope of <1%. The incident rays in the excitation light path and the transmission light path are at an incident angle of 45°±1° with the corresponding mirror surface.
4. The fluorescent quantum dot detection optical system according to claim 1, characterized in that: The numerical aperture of the objective lens is between 0.4 and 0.
8. The tube lens is matched with the objective lens, with a focal length of 200mm and a wavefront error of <λ / 4 RMS @546nm.
5. The fluorescent quantum dot detection optical system according to claim 1, characterized in that: The light source is set to an adjustable power LED with a wavelength of 440nm; The collimation assembly consists of a convex lens group and an aperture. The excitation light emitted by the light source is converted into a parallel beam by the convex lens group and the aperture in sequence. The homogenization component is configured to work in conjunction with a compound eye lens array and an integrating mirror. The excitation light emitted by the collimation component is sequentially split by the compound eye lens array, and the integrating mirror superimposes the multiple channels.
6. The fluorescent quantum dot detection optical system according to claim 1, characterized in that: The filter group is set as a three-channel emission filter of BP655 / 20, BP565 / 20 and BP590 / 30. The filter is placed on the turntable by a pressure plate and the turntable is driven by a stepper motor to switch channels.
7. The fluorescent quantum dot detection optical system according to claim 1, characterized in that: The camera has a quantum efficiency of >90% at 650nm and noise of <1e-.