TWI465709B - Apparatus for fluorescence enhancement - Google Patents

Description

Fluorescent enhancer

This invention relates to fluorescent enhancement devices, and more particularly to fluorescent enhancement devices utilizing photonic crystals.

Fluorescent detection technology is a common detection application for environmental, biomedical, food, etc. Fluorescence detection often suffers from low fluorescence intensity and affects the detection effect of fluorescent detection. The photonic crystal has a special optical energy gap and can be applied to improve the excitation light intensity and the fluorescence extraction efficiency, and is one of the methods for improving the fluorescence detection sensitivity in recent years. However, the photonic crystal fluorescent detector currently designed can only be used in a single use, and the reaction time is long, so it is impossible to perform multiple or continuous monitoring.

The currently known technology or literature directly contacts the fluorescent material with the photonic crystal, whereby the optical energy gap of the photonic crystal overlaps with the fluorescent wavelength of the fluorescent material (partially containing a light energy gap overlapping the wavelength of the excitation light) , to achieve the effect of enhanced fluorescence intensity. Cui et al. (Anal. Methods, 2010, 2, 448-450.) use a fluorescent material that can detect mercury ions to mix with a photonic crystal. The photonic energy gap of the photonic crystal overlaps with the wavelength of the fluorescent light to improve the fluorescence detection sensitivity. Li et al. (Journal of Colloid and Interface Science 356, 2011, 63-68.) utilize two photonic crystals of different optical energy gaps, one of which overlaps with the excitation light and the other of which overlaps with the fluorescent light. When the fluorescent material penetrates into the photonic crystal composite layer, the effect of improving the fluorescence intensity is achieved. However, none of the prior art photonic crystal sensors described above have a reusable function. The direct contact of the fluorescent material with the photonic crystal causes the problem of mass transfer of the analyte between the photonic crystals, limits the detection and cleaning efficiency, and destroys the photonic crystal structure and the characteristics of the fluorescent material in the repeated use, resulting in a photonic crystal sensation. The detector cannot be reused multiple times and there is no continuous monitoring application capability. In addition, the phosphor material is mixed with the photonic crystal, and some of the light is reflected by the photonic crystal to the opposite direction of the optical detector, thereby reducing the intensity of the fluorescent light that can be detected.

In summary, the development of a reusable photonic crystal sensor that enhances fluorescence intensity is currently a goal.

One of the objects of the present invention is to develop a fluorescence enhancement device that can re-use a photonic crystal for sensing and enhance fluorescence intensity.

According to an embodiment of the invention, a fluorescent enhancement device includes a light source, a phosphor layer, a first photonic crystal layer, and a second photonic crystal layer. The light source can emit excitation light to excite the fluorescent material in the layer of phosphor material to emit fluorescence. The first photonic crystal layer and the second photonic crystal layer are disposed downstream of the incident direction of the excitation light of the phosphor layer. The optical energy gap of the first photonic crystal of the first photonic crystal layer overlaps with the wavelength of the excitation light, whereby the first photonic crystal layer reflects the excitation light to the phosphor material layer. The second photonic crystal optical energy gap of the second photonic crystal layer overlaps with the fluorescent wavelength of the fluorescent material to reflect the fluorescent light emitted by the fluorescent material.

The purpose, technical contents, features, and effects achieved by the present invention will become more apparent from the detailed description of the appended claims.

1‧‧‧Light source

2‧‧‧Fluorescent material layer

21‧‧‧Fluorescent materials

3‧‧‧First photonic crystal layer

4‧‧‧Second photonic crystal layer

5‧‧‧Transparent substrate

6‧‧‧ Carrier

1 and 2 are schematic views showing a fluorescent enhancement device according to an embodiment of the present invention.

3 is a spectral absorption diagram showing the optical energy gap of the first and second photonic crystals and the wavelength range of the excitation light and the fluorescent material.

Fig. 4 is a graph showing experimental results showing fluorescence enhancement results obtained by reflecting excitation light and fluorescence in a photonic crystal according to an embodiment of the present invention.

Fig. 5 is a graph showing experimental data showing that the concentration of copper ions in water according to an embodiment of the present invention corresponds to the fluorescence intensity.

Fig. 6 is a graph showing experimental data showing the relationship between the concentration of copper ions in water and the amount of fluorescence quenching in an embodiment of the present invention.

Please refer to FIG. 1 and FIG. 2 , which are schematic diagrams showing a fluorescent enhancement device according to an embodiment of the present invention, comprising a light source 1 , a phosphor layer 2 , a first photonic crystal layer 3 and a second photonic crystal layer 4 . The light source 1 can emit excitation light to excite the fluorescent material 21 in the phosphor material layer 2 to emit fluorescence (the dotted line portion of Fig. 2).

The first photonic crystal layer 3 and the second photonic crystal layer 4 are disposed downstream of the incident direction of the excitation light of the phosphor layer 2. The optical energy gap of the first photonic crystal of the first photonic crystal layer 3 overlaps with the wavelength of the excitation light, so that the first photonic crystal layer 3 reflects the excitation light to the phosphor material layer 2, as shown in FIG. The phosphor material 21 of the material layer 2 is again excited to emit fluorescence.

The second photonic crystal optical energy gap of the second photonic crystal layer 4 overlaps with the fluorescent wavelength of the fluorescent material 21, thereby reflecting the fluorescent light emitted by the fluorescent material 21, as shown in FIG. 2, thereby increasing the fluorescence intensity.

The photonic crystal referred to herein is a periodic dielectric distribution structure, and the first photonic crystal and the second photonic crystal of the present invention may be arranged in one, two or three dimensions. In a preferred embodiment, the first photonic crystal and the second photonic crystal are one-dimensionally arranged, and the function is total reflection. Membrane to reflect excitation or fluorescence. The one-dimensional array of photonic crystals may include a distributed Bragg reflector (DBR).

In one embodiment, the first and second photonic crystal systems are formed by self-assembly of a micron sphere, wherein the composition of the microspheres is an organic polymer, an inorganic component, or a combination thereof. The organic polymer herein may include, but is not limited to, a polystyrene series, a polymethyl methacrylate series, a polymaleic acid series, a polylactic acid series, a polyamino acid series polymer, or a combination thereof. Inorganic components can include, but are not limited to, tantalum, titanium, zirconium, gold, silver, iron, aluminum, copper, nickel metal, metal oxides thereof, or combinations thereof. In addition, the microsphere composition may be composed of an organic-inorganic component, which may include, but is not limited to, carbon-germanium, carbon-titanium, carbon-zirconium, carbon-aluminum series materials, and combinations thereof.

As shown in FIG. 1, the first photonic crystal layer 3 is disposed upstream of the incident direction of the excitation light of the second photonic crystal layer 4. However, the relative position of the first photonic crystal layer 3 and the second photonic crystal layer 4 can be adjusted. In another embodiment of the present invention, the second photonic crystal layer 4 is disposed at the excitation of the first photonic crystal layer 3. Upstream of direction.

The light source 1 shown in FIG. 1 is disposed above the first photonic crystal layer 3 and the second photonic crystal layer 4; however, the light source 1 may also be disposed under the first photonic crystal layer 3 and the second photonic crystal layer 4 or It is another relative position as long as the light source 1 can be incident on the phosphor layer 2 and the first photonic crystal layer 3.

In addition, as shown in FIG. 1, the fluorescent enhancement device of the present invention comprises a transparent substrate 5 disposed between the second reflective layer and the first reflective layer, whereby the first photonic crystal layer 3 and the second photonic crystal are known. Layer 4 is separable. Furthermore, the second photonic crystal layer 4 can be disposed on a carrier 6.

In one embodiment, a small area can be constructed from two coverslips to define the firefly. The light material layer 2 is such that the fluorescent material 21 can be placed. However, other ways of defining the fluorescent material layer 2 are also feasible, as long as the fluorescent material and the light transmission are achieved.

A person skilled in the art may know the diversity of fluorescent materials, which may be roughly classified into organic fluorescent molecules and inorganic fluorescent molecules, which are not detailed herein, wherein organic fluorescent molecules include, but are not limited to, tluorescent proteins. .

In one embodiment, the phosphor material comprises a quantum dot, such as but not limited to CdS, CdSe, CdTe, CdPo, ZnS, ZnSe, ZnTe, ZnPo, MgS, MgSe, MgTe, PbSe, PbS, PbTe, HgS, HgSe. Or HgTe.

The optical energy gap of the first photonic crystal and the second photonic crystal is adjusted by the particle size of the microspheres and the effective refractive index.

Please refer to the above formula for the optical energy gap (T. Endo et al./Sensors and Actuators B 125 (2007) 589-595), which is derived from the Bragg formula, where m refers to the diffraction level; λ _peak is the diffraction peak wavelength. d ₁₁₁ is the inter-frame distance of the (111) plane; θ is the angle between the incident light and the normal of the refractive surface; n _eff is the average refractive index of the lattice. Where in the face-centered cubic crystal (FCC) structure closely packed in the (111) phase, d ₁₁₁ = 0.816D, where D refers to the radius of the sphere.

For example, the fluorescent enhancement device of the present invention can be used for detection, and the application field includes, but is not limited to, environment, biomedicine, food. In one embodiment, an object to be tested (not shown) may be placed on the layer of phosphor material to co-react with the phosphor material to detect the concentration of the analyte.

The purpose, the technical content, the features and the achieved effects of the present invention can be more easily understood by the following detailed description of the embodiments with reference to the accompanying drawings. This is not intended to limit the scope of the invention.

Preparation of photonic crystals

Please refer to FIG. 3 , which is a spectral absorption diagram showing the optical energy gap of the first and second photonic crystals and the reflection, absorption wavelength and intensity of the excitation light corresponding to the fluorescent material. The first photonic crystal is self-assembled opal with 160 nm styrene microspheres, and the gap is filled with silica, hereinafter referred to as PC160nm, which is used to reflect the excitation light, wherein the excitation light is LED 395 nm. In this embodiment, a three-dimensional photonic crystal structure is prepared by gravity sedimentation self-assembly method, and the thickness of the opal (photonic crystal) prepared by the method can be greater than 100 micrometers. The second photonic crystal is self-assembled opal with 240 nm styrene microspheres, and the gap is filled with silica, hereinafter referred to as PC240nm for reflecting fluorescence, wherein the fluorescent substance is CdS/ZnS quantum dots, fluorescent The peak is 554 nm.

Fluorescence detection

Chemically synthesized CdS/ZnS core-shell quantum dots (mercaptoacetic acid as a stabilizer), used as a fluorescent sensing material for copper ion concentration detection in water, and using Ocean Optics LED 395nm as excitation source. The copper ion fluorescence detection in water is carried out. Figure 3 shows the fluorescence spectrum of the 395 nm excitation light and the excited CdS/ZnS core-shell quantum dots. Figure 4 shows the CdS/ZnS core-shell quantum dots reflected by the photonic crystal. The resulting fluorescence enhancement results in which the first photonic crystal PC160 and the second photonic crystal PC240 were simultaneously added, and the efficiency of the fluorescence enhancement factor was significantly increased compared with the control group and only the PC160 and PC240 groups.

5 is a double-reflection photonic crystal sensor of the present invention combined with a CdS/ZnS core-shell quantum dot to detect the overall concentration of copper ions in water, and FIG. 6 is a copper ion concentration and fluorescence quenching in water. The quantitative relationship, in which fluorescence quenching refers to the phenomenon that the excited fluorescent molecules lose energy by various external conversion processes to reduce the fluorescence intensity. The test results show that the present invention can increase the fluorescence intensity by 23.7 times, and the fluorescence intensity decreases with the increase of the copper ion concentration in the water, and the amount of fluorescence quenching can be used as the basis for detecting the copper ion concentration in the water.

In summary, the present invention combines a plurality of photonic crystal layers respectively overlapping excitation light and fluorescence wavelength, and constructs a small container capable of placing a sample of a fluorescent material or a fluorescent material mixed with a sample to be tested. In this way, in addition to the enhanced fluorescence intensity of the fluorescent detection, the detection sample and the fluorescent substance can be prevented from being contaminated by contact with the photonic crystal structure, so that the detector using the photonic crystal can be repeatedly used, and has Continuously enhance the detection capability of fluorescent performance to expand the range of practical applications of photonic crystals.

The embodiments described above are merely illustrative of the technical spirit and the features of the present invention, and the objects of the present invention can be understood by those skilled in the art, and the scope of the present invention cannot be limited thereto. That is, the equivalent variations or modifications made by the spirit of the present invention should still be included in the scope of the present invention.

1‧‧‧Light source

2‧‧‧Fluorescent material layer

21‧‧‧Fluorescent materials

3‧‧‧First photonic crystal layer

4‧‧‧Second photonic crystal layer

5‧‧‧Transparent substrate

6‧‧‧ Carrier

Claims (16)

A fluorescent enhancement device for fluorescence detection and comprising: a light source for emitting an excitation light; a phosphor material layer comprising a fluorescent material, wherein the excitation light is used to excite the fluorescent material to emit a first photonic crystal layer for reflecting the excitation light to the phosphor material layer, comprising a first photonic crystal, the optical energy gap of the first photonic crystal overlapping the wavelength of the excitation light; a second photonic crystal layer for reflecting the fluorescent material of the fluorescent material, comprising a second photonic crystal, wherein a light energy gap of the second photonic crystal overlaps with a fluorescent wavelength of the fluorescent material, wherein the A photonic crystal layer and the second photonic crystal layer are disposed downstream of the excitation light incident direction of the phosphor material layer. The fluorescence enhancement device of claim 1, wherein the first photonic crystal and the second photonic crystal are arranged in one, two or three dimensions. The fluorescent enhancement device of claim 1, wherein the first photonic crystal and the second photonic crystal are one-dimensionally arranged. The fluorescent enhancement device of claim 1, wherein the first photonic crystal layer is disposed upstream of the excitation light incident direction of the second photonic crystal layer. The fluorescence enhancement device of claim 1, wherein the second photonic crystal layer is disposed upstream of the excitation light incident direction of the first photonic crystal layer. The fluorescent enhancement device of claim 1, wherein the first photonic crystal layer and the second photonic crystal layer are separably designed. The fluorescent enhancement device of claim 1, further comprising: a transparent substrate disposed between the second photonic crystal layer and the first photonic crystal layer. The fluorescence enhancement device of claim 1, wherein the first photonic crystal and the second photonic crystal system are formed by self-assembly of a plurality of microspheres. The fluorescent enhancement device of claim 8, wherein the composition of the microspheres is an organic polymer, an inorganic component or a combination thereof. The fluorescent enhancement device of claim 9, wherein the organic polymer is selected from the group consisting of polystyrene series, polymethyl methacrylate series, polymaleic acid series, polylactic acid series, polyamino acid series polymer and The above combination. The fluorescent enhancement device of claim 9, wherein the inorganic component is selected from the group consisting of ruthenium, titanium, zirconium, gold, silver, iron, aluminum, copper, nickel metal, metal oxides thereof, and combinations thereof. The fluorescent enhancement device of claim 9, wherein the composition of the microspheres is selected from the group consisting of carbon-germanium, carbon-titanium, carbon-zirconium, carbon-aluminum series materials, and combinations thereof. The fluorescent enhancement device of claim 8, wherein the optical energy gap of the first photonic crystal and the second photonic crystal is adjusted by the particle size of the microspheres. The fluorescent enhancement device of claim 1, wherein the fluorescent material comprises a quantum dot. The fluorescence enhancement device of claim 14, wherein the quantum dots are selected from the group consisting of CdS, CdSe, CdTe, CdPo, ZnS, ZnSe, ZnTe, ZnPo, MgS, MgSe, MgTe, PbSe, PbS, PbTe, HgS, HgSe and HgTe. The fluorescent enhancement device of claim 1 is configured to detect a test object, wherein the test object is located in the fluorescent material layer.