CN114324568A - Acoustic field-assisted preparation of guanine peptide nucleic acid self-assembled nanosphere-based photonic crystals - Google Patents

Abstract

The invention discloses a sound field auxiliary preparation method of guanine peptide nucleic acid self-assembly nanosphere-based photonic crystals. Taking guanine peptide nucleic acid self-assembly nanospheres as a light reflection functional medium material, forming photonic crystals by adopting a compact hexagonal packing structure, and rapidly forming the photonic crystals by combining sound field control and micro-fluidic control; the morphology and the particle size of the self-assembled nanospheres are regulated and controlled by regulating the influence factors of self-assembly and the nucleic acid molecular structure of the guanine peptide, the arrangement is regulated and controlled by regulating and controlling sound field parameters, and finally the wavelength of the reflected light of the photonic crystal is regulated and controlled. The invention realizes the preparation of guanine peptide nucleic acid self-assembly nanosphere-based photonic crystals by utilizing a sound field, has good biocompatibility and excellent optical performance and dynamic response characteristic, and the photonic crystals can change lattice parameters under external excitation so as to realize the translation of reflected light wavelength and the change of visual color.

Description

Acoustic field-assisted preparation of guanine peptide nucleic acid self-assembled nanosphere-based photonic crystals

technical field

The invention relates to a preparation method of a biological organic photonic crystal, in particular to a sound field-assisted preparation of a guanine peptide nucleic acid self-assembled nanosphere-based photonic crystal.

Background technique

Photonic crystals are periodically stacked in order and regularity through media with different dielectric constants, which can achieve selective reflection of incident light. Compared with traditional dyes and fluorescent substances, photonic crystals have the characteristics of adjustable reflected light and difficult quenching of reflected light, which can realize optical anti-counterfeiting, optical information storage, signal transmission and other functions. There are broad application prospects in the fields of interaction, micro-strain detection, colorimetric sensing, and photonic chips.

At present, most photonic crystals use inorganic oxides (such as silicon dioxide, titanium dioxide, etc.) and high molecular polymers (such as polystyrene, polyurethane, etc.) as functional medium materials; the preparation process usually adopts laser direct writing etching, three-dimensional printing, etc. , stencil printing and colloidal self-assembly. However, although photonic crystals prepared from polymer photonic crystals and inorganic oxides have high physicochemical stability and narrow reflection bandwidth, they can be applied in the fields of optical information expression and optical anti-counterfeiting. With the development of medical sensing, photonic crystals with good biocompatibility will become an inevitable trend in the development of this field. The weak biocompatibility leads to biological rejection of traditional photonic crystals, and the array shape is not easy to control, the preparation cycle is long, and the preparation process is complicated, which is difficult to meet the development requirements of a new generation of biocompatible photonic crystals.

SUMMARY OF THE INVENTION

Based on the above technical background, combined with the inherent biocompatibility of base and peptide molecules, the easy regulation of self-assembly morphology, and the sound field-assisted regulation of the array morphology, the present invention proposes a guanine peptide nucleic acid self-assembled nanosphere A sound field-assisted preparation method of a base photonic crystal.

The invention realizes the preparation of the guanine peptide nucleic acid self-assembled nanosphere-based photonic crystal by using the sound field, and has both good biocompatibility and excellent optical performance and dynamic response characteristics.

The technical scheme adopted by the present invention to solve its technical problems is as follows:

The method is to prepare guanine peptide nucleic acid self-assembled nanospheres by means of bulk acoustic wave sound field assistance. The guanine peptide nucleic acid self-assembled nanospheres are self-assembled from guanine peptide nucleic acid.

The method adopts the bulk acoustic wave transducer to form the auxiliary mode of the bulk acoustic wave sound field.

The guanine peptide nucleic acid self-assembled nanosphere-based photonic crystal is encapsulated by polyethylene glycol diacrylate (PEGDA200) with an average molecular weight of 200.

Specifically prepared by the following method:

1) Select the guanine peptide nucleic acid powder to dissolve in ultrapure water, and then stand at a constant temperature of 25°C and a constant humidity of 80% for 36 hours to prepare a suspension of guanine peptide nucleic acid self-assembled nanospheres;

2) The substrate is pre-arranged at the bottom of the bulk acoustic wave transducer, the suspension is pumped into the chamber of the bulk acoustic wave transducer, and the signal generator of the bulk acoustic wave transducer is turned on to adjust the excitation frequency to form a stable and consistent chamber. standing wave field;

3) After standing until the guanine peptide nucleic acid self-assembled nanospheres form a stable arrangement in the standing wave field of bulk acoustic waves, the excess suspension in the chamber is removed, so that the guanine peptide nucleic acid self-assembled nanospheres are slowly deposited on the surface of the substrate, A substrate with guanine peptide nucleic acid self-assembled nanosphere-based photonic crystals is prepared, and a guanine peptide nucleic acid self-assembled nanosphere-based photonic crystal is obtained.

The present invention uses guanine peptide nucleic acid self-assembled nanospheres as functional medium materials, so that the photonic crystal product has inherent biocompatibility and other designated bioactive functions on the basis of excellent optical properties.

The guanine peptide nucleic acid self-assembled nanosphere-based photonic crystal adopts a glass sheet, a quartz sheet, a silicon wafer or a flexible substrate as a substrate, and the flexible substrate is a polydimethylsiloxane film or the like.

The morphology control (particle size, hollow/solid, smooth or rough surface, etc.) of guanine peptide nucleic acid self-assembled nanospheres is realized by adjusting the molecular structure of guanine peptide nucleic acid.

specifically,

Adjust the degree of hollow/solid in the self-assembled nanospheres of guanine peptide nucleic acid by adjusting the length and type of hydrophilic and hydrophobic groups in the molecular structure of guanine peptide nucleic acid;

By adjusting the number and types of hydrophilic and hydrophobic groups in the molecular structure of guanine peptide nucleic acid, the degree of surface smoothness/roughness in the self-assembled nanospheres of guanine peptide nucleic acid can be adjusted.

The particle size of guanine peptide nucleic acid self-assembled nanospheres can be controlled by adjusting the temperature.

The arrangement of guanine peptide nucleic acid self-assembled nanosphere-based photonic crystals can be controlled by adjusting the sound field parameters;

Combined with particle size regulation and arrangement regulation, the regulation of the reflected light wavelength of the guanine peptide nucleic acid self-assembled nanosphere-based photonic crystal is realized.

The guanine peptide nucleic acid is an amino acid-like structure with guanine as a side chain group and an amide bond as a molecular skeleton, and the groups used for artificial synthesis of guanine peptide nucleic acid are diphenylmethoxycarbonyl (Bhoc), 9- Fluorene methoxycarbonyl (Fmoc), glycine, aminoethyl, acetyl and guanine groups.

The specific molecular formula of the guanine peptide nucleic acid is Bhoc-G-(Bhoc)-aeg-OH, Bhoc-G, Fmoc-G, Fmoc-G-(Fmoc)-aeg-OH, G-(Bhoc)-aeg- OH, Fmoc-G-aeg-OH, Fmoc-G-(Bhoc)-aeg-OH.

The guanine peptide nucleic acid self-assembled nanospheres are arranged in the bulk acoustic wave transducer with the aid of the standing wave field of bulk acoustic waves, and the shape of the arrangement is a one-dimensional stripe, a two-dimensional lattice shape or a two-dimensional curve shape, and a two-dimensional shape. The curvilinear shape is, in particular, a wavy shape.

The bulk acoustic wave transducer formed in a two-dimensional lattice shape is mainly composed of a three-dimensional printing chamber, two pairs of vertically distributed piezoelectric ceramics and a micro-channel controlled by a syringe pump.

The BAW transducers arranged in the shape of one-dimensional stripes are mainly composed of a three-dimensional printing chamber, a pair of vertically distributed piezoelectric ceramics and a microfluidic channel controlled by a syringe pump.

The bulk acoustic wave transducer forms a frequency-tunable bulk acoustic wave standing wave field in the guanine peptide nucleic acid self-assembled nanosphere suspension.

The guanine peptide nucleic acid self-assembled nanosphere-based photonic crystal is arranged with the aid of a bulk acoustic wave sound field, and the lattice spacing is greater than or equal to 20 microns, and the fringe array spacing is greater than or equal to 20 microns.

The guanine peptide nucleic acid self-assembled nanosphere-based photonic crystal is further processed by the following process to complete the complete encapsulation preparation:

1) Weighing 5 milliliters of polyethylene glycol diacrylate with an average molecular weight of 200, adding a mixed photoinitiator TPO-L that accounts for 0.8% of the polyethylene glycol diacrylate mass fraction to form a mixture;

2) fully mixing and defoaming the mixture using a planetary stirrer to prepare a photosensitive prepolymer;

3) placing the substrate with the guanine peptide nucleic acid self-assembled nanosphere-based photonic crystal on a spin coater, and evenly dropping the photosensitive prepolymer on the surface of the guanine peptide nucleic acid self-assembled nanosphere-based photonic crystal without the substrate, A uniform thin film is formed on the surface of the guanine peptide nucleic acid self-assembled nanosphere-based photonic crystal by a spin coating method, and UV light curing is used to complete the encapsulation of the guanine peptide nucleic acid self-assembled nanosphere-based photonic crystal.

In the step 3), use ultraviolet light with a wavelength of 405 nm to cure for 20 seconds.

The self-assembled nanosphere-based photonic crystal of guanine peptide nucleic acid has a height of less than 5 mm and a diameter of more than 20 mm after being packaged.

The guanine peptide nucleic acid self-assembled nanosphere-based photonic crystal is prepared by processing the guanine peptide nucleic acid self-assembled nanospheres with the aid of bulk acoustic wave sound field.

The guanine peptide nucleic acid self-assembled nanospheres of the present invention can be used as light-reflecting functional medium materials, and photonic crystals can be formed by adopting a close hexagonal stacking structure, and silicon dioxide sheets, polydimethylsiloxane films, quartz sheets, etc. Ethylene glycol diacrylate is used for encapsulation, and the rapid prototyping of photonic crystals is carried out by the combination of sound field manipulation and microfluidics. The morphology and particle size of guanine peptide nucleic acid self-assembled nanospheres can be regulated by adjusting the environmental conditions and molecular structure of self-assembly. Arrangement regulation; thereby realizing the regulation of the reflected light wavelength of the guanine peptide nucleic acid self-assembled nanosphere-based photonic crystal.

The photonic crystal of the present invention can change lattice parameters under external excitation (such as temperature, bending, stretching, magnetic field, electric field, pH, humidity), thereby realizing the translation of reflected light wavelength and the change of visual color.

The photonic crystal of the present invention adopts guanine peptide nucleic acid self-assembled nanospheres as functional medium materials, and utilizes the diffraction principle of light to form a one-dimensional or two-dimensional regular and orderly stacking of guanine peptide nucleic acid self-assembled nanospheres to form different Guanine peptide nucleic acid self-assembled nanosphere-based photonic crystals with selective reflection of angle incident light, and the preparation of guanine peptide nucleic acid self-assembled nanosphere-based photonic crystals by means of sound field assistance.

The invention adopts the means assisted by the sound field to prepare the guanine peptide nucleic acid self-assembled nanosphere-based photonic crystal. Modulation of the morphology of nucleic acid self-assembled nanosphere arrays.

The guanine peptide nucleic acid self-assembled nanosphere-based photonic crystal of the present invention can use the methods of molecular modification and self-assembly condition control to control the size and shape of the nanospheres, thereby realizing the optical properties of the guanine peptide nucleic acid nanosphere-based photonic crystal. regulation.

The beneficial effects that the present invention has are:

(1) By designing and modifying the molecular structure of guanine peptide nucleic acid, the morphology (hollow/solid, smooth or rough surface, etc.) of guanine peptide nucleic acid self-assembled nanospheres can be controlled;

(2) By controlling the self-assembly conditions (such as temperature, etc.), the particle size regulation of the guanine peptide nucleic acid self-assembled nanospheres in the guanine peptide nucleic acid self-assembled nanosphere-based photonic crystal is realized, so as to realize the regulation of the optical properties of the photonic crystal;

(3) By orderly stacking and arranging guanine peptide nucleic acid self-assembled nanospheres, selective reflection of incident light is achieved while maintaining good biocompatibility;

(4) By adjusting the hydrophilicity and hydrophobicity of the guanine peptide nucleic acid self-assembled nanosphere-based photonic crystal substrate, the frequency and voltage amplitude of the sound field, and the microfluidic pumping speed, the self-assembled nanosphere-based photonic crystal of guanine peptide nucleic acid can be realized. Morphology and structure control.

Description of drawings

Fig. 1 is a schematic diagram of the preparation process of guanine peptide nucleic acid self-assembled nanosphere suspension;

Fig. 2 is the scanning electron microscope image of surface rough solid guanine peptide nucleic acid self-assembled nanospheres;

Figure 3 is a scanning electron microscope image of a solid guanine peptide nucleic acid self-assembled nanosphere with smooth surface;

Figure 4 is a scanning electron microscope image of a hollow guanine peptide nucleic acid self-assembled nanosphere with smooth surface;

Figure 5 is a schematic diagram of the structure of guanine peptide nucleic acid self-assembled nanospheres;

Fig. 6 is the particle size statistics diagram of guanine peptide nucleic acid self-assembled nanospheres prepared at 4 degrees Celsius;

Fig. 7 is the particle size statistics diagram of guanine peptide nucleic acid self-assembled nanospheres prepared at 25 degrees Celsius;

Fig. 8 is the particle size statistics diagram of guanine peptide nucleic acid self-assembled nanospheres prepared at 75 degrees Celsius;

Figure 9 is a confocal microscope image of the fringe arrangement of guanine peptide nucleic acid self-assembled nanosphere-based photonic crystals at different pumping speeds;

Fig. 10 is the actual picture of guanine peptide nucleic acid nanosphere-based photonic crystals prepared under different self-assembly temperatures;

Fig. 11 is the transmitted light spectrum of guanine peptide nucleic acid self-assembled nanosphere-based photonic crystal;

Figure 12 is a graph showing the relationship between the transmission peak value of the guanine peptide nucleic acid self-assembled nanosphere-based photonic crystal and the bending angle of the photonic crystal.

Detailed ways

The present invention will be further described below with reference to the accompanying drawings and examples, but the embodiments of the present invention are not limited thereto.

The embodiment of the present invention and its implementation process are as follows:

Specific Example 1

Take 4 mg of guanine peptide nucleic acid in a beaker, add ultrapure water at a ratio of 2 mg/ml, heat it to above 90 degrees Celsius in a water bath, and prepare a guanine peptide nucleic acid solution with magnetic stirring. The prepared solution was allowed to stand at 25 degrees Celsius and 80% constant humidity for 36 hours to complete the self-assembly of the guanine peptide nucleic acid. The self-assembled structure of solid guanine peptide nucleic acid self-assembled nanospheres obtained by self-assembly of guanine peptide nucleic acid is shown in Figure 2, and the self-assembled structure of self-assembled solid guanine peptide nucleic acid nanospheres is shown in Figure 3. The hollow guanine peptide nucleic acid self-assembled nanospheres with smooth surface are shown in Figure 4.

It can be seen from this example that the particle size and surface morphology (such as hollow/solid, smooth or rough surface, etc.) of guanine peptide nucleic acid self-assembled nanospheres can be adjusted by adjusting the number and type of hydrophilic and hydrophobic groups in the molecular structure of guanine peptide nucleic acid. etc. to control.

Specific embodiment 2

As shown in Figure 1, take 12 mg of guanine peptide nucleic acid (specific molecular formula is Fmoc-G-(Bhoc)-aeg-OH) in a beaker, add ultrapure water at a ratio of 2 mg/ml and heat it to 90 degrees Celsius using a water bath In the above, the guanine peptide nucleic acid solution was prepared with magnetic stirring. Divide the prepared solution into three equal parts and let stand for 36 hours at 4 degrees Celsius, 25 degrees Celsius and 75 degrees Celsius under 80% constant humidity, so that the self-assembly of guanine peptide nucleic acid is complete, and the self-assembly of hollow guanine peptide nucleic acid with different particle sizes is obtained. Nanospheres. The appearance of guanine peptide nucleic acid self-assembled nanospheres is shown in Figure 4, the structure of guanine peptide nucleic acid self-assembled nanospheres is shown in Figure 5, and the particle size statistics of guanine peptide nucleic acid self-assembled nanospheres are shown in Figure 6-8 Show.

It can be seen from this example that the particle size of the guanine peptide nucleic acid self-assembled nanospheres can be adjusted by adjusting the self-assembly environment (such as temperature, etc.) of the guanine peptide nucleic acid.

Specific embodiment 3

(1) As shown in Figure 1, take 12 mg of guanine peptide nucleic acid (specific molecular formula is Fmoc-G-(Bhoc)-aeg-OH) in a beaker, add ultrapure water at a rate of 2 mg/ml and use a water bath Heat to above 90 degrees Celsius, and prepare a guanine peptide nucleic acid solution with magnetic stirring. The prepared solution was allowed to stand at 25 degrees Celsius and a constant humidity of 80% for 36 hours, so that the self-assembly of guanine peptide nucleic acid was completed, and a suspension of guanine peptide nucleic acid self-assembled nanospheres was obtained.

(2) The concretely implemented one-dimensional and two-dimensional bulk acoustic wave transducers include three-dimensional printing chambers, piezoelectric ceramics and micro-channel parts. Taking the photonic crystal with one-dimensional arrangement of guanine peptide nucleic acid nanospheres prepared by self-assembly at 25 degrees Celsius as an example, a three-dimensional printing chamber with piezoelectric ceramics is arranged on the substrate, and the prepared guanine peptide is injected by a syringe pump. The nucleic acid self-assembled nanosphere suspension is pumped into the open chamber through the microfluidic pipeline from the suspension inflow inlet.

(3) After the self-assembled nanosphere suspension is completely pumped into the chamber, the signal generator is activated and an electrical signal with a frequency of f1 is output, and the piezoelectric ceramic generates a standing wave field of bulk acoustic waves in the chamber. When the suspension of guanine peptide nucleic acid self-assembled nanospheres flows through the standing wave field of bulk acoustic wave, it is subjected to the acoustic radiation force of controllable intensity, moves different distances in the width direction of the chamber, and reaches the node position of the standing wave field of bulk acoustic wave. Complete the arrangement. After the guanine peptide nucleic acid self-assembled nanospheres are completely arranged, use a syringe pump to remove the excess liquid in the chamber at a speed of 10-100 μl/min along the outflow port of the suspension, so that the guanine peptide nucleic acid self-assembled nanospheres can be uniform. It is deposited on the surface of the substrate, and then the bulk acoustic wave transducer is removed to form a one-dimensionally arranged striped guanine peptide nucleic acid self-assembled nano-based photonic crystal. Figure 9 shows the morphologies of guanine peptide nucleic acid self-assembled nanosphere-based photonic crystals at different pumping speeds.

(4) Take 5 milliliters of polyethylene glycol diacrylate (PEGDA200) with an average molecular mass of 200, add a photoinitiator (TPO-L) occupying 0.8% of the mass fraction of polyethylene glycol diacrylate, and prepare for the Photosensitive prepolymers encapsulated by purine peptide nucleic acid self-assembled nanosphere-based photonic crystals.

(5) The photosensitive prepolymer is uniformly coated on the surface layer of the guanine peptide nucleic acid self-assembled nanosphere-based photonic crystal by the spin coating method, and then the photosensitive prepolymer is cured with 405 nm ultraviolet light to complete the guanine peptide nucleic acid nanosphere Encapsulation of base photonic crystals.

Figure 10 shows the actual picture of guanine peptide nucleic acid self-assembled nanosphere-based photonic crystals prepared from guanine peptide nucleic acid nanospheres with different particle sizes.

(6) The optical properties of the prepared guanine peptide nucleic acid self-assembled nanosphere-based photonic crystals were characterized.

Figure 11 shows the transmission spectrum in the visible light region at different incident angles, and the relationship between the transmission peak and the bending angle of the guanine peptide nucleic acid self-assembled nanosphere-based photonic crystal and the theoretical value curve are shown in Figure 12.

It can be seen from this embodiment that the present invention realizes the sound field-assisted preparation of guanine peptide nucleic acid self-assembled nanosphere-based photonic crystals, the operation is simple, the process conditions are mild, the process equipment is simple, and the prepared guanine peptide nucleic acid self-assembled nanosphere-based photonic crystals Has excellent biocompatibility and optical properties.

Claims (9)

1. a sound field auxiliary preparation method of guanine peptide nucleic acid self-assembled nanosphere-based photonic crystal, is characterized in that: the method is to prepare by adopting bulk acoustic wave sound field auxiliary mode by guanine peptide nucleic acid self-assembled nanosphere, and described guanine Peptide nucleic acid self-assembled nanospheres are self-assembled from guanine peptide nucleic acid. 2 . The sound field-assisted preparation method of a guanine peptide nucleic acid self-assembled nanosphere-based photonic crystal according to claim 1 , wherein the method adopts a bulk acoustic wave transducer to form the bulk acoustic wave sound field-assisted mode. 3 . 3. the sound field auxiliary preparation method of a kind of guanine peptide nucleic acid self-assembled nano-sphere-based photonic crystal according to claim 1, is characterized in that: described guanine peptide nucleic acid self-assembled nano-sphere-based photonic crystal uses an average molecular weight of 200 polyethylene glycol diacrylate for encapsulation. 4. the sound field auxiliary preparation method of a kind of guanine peptide nucleic acid self-assembled nanosphere-based photonic crystal according to claim 1, is characterized in that: specifically adopt following method process preparation: 1) Select the guanine peptide nucleic acid powder to dissolve in ultrapure water, and then stand at a constant temperature of 25°C and a constant humidity of 80% for 36 hours to prepare a suspension of guanine peptide nucleic acid self-assembled nanospheres; 2) The substrate is pre-arranged at the bottom of the BAW transducer, the suspension is pumped into the chamber of the BAW transducer, and the signal generator of the BAW transducer is turned on to adjust the excitation frequency to form a standing wave field in the chamber ; 3) After standing until the guanine peptide nucleic acid self-assembled nanospheres form a stable arrangement in the standing wave field of bulk acoustic waves, the excess suspension in the chamber is removed, so that the guanine peptide nucleic acid self-assembled nanospheres are deposited on the surface of the substrate to obtain Guanine peptide nucleic acid self-assembled nanosphere-based photonic crystals. 5. the sound field auxiliary preparation method of a kind of guanine peptide nucleic acid self-assembled nanosphere-based photonic crystal according to claim 1 or 4, it is characterized in that: described guanine peptide nucleic acid self-assembled nanosphere-based photonic crystal adopts glass wafers, quartz wafers, silicon wafers or flexible substrates as substrates. 6. The sound field-assisted preparation method of a kind of guanine peptide nucleic acid self-assembled nanosphere-based photonic crystal according to claim 4, it is characterized in that: realize guanine peptide nucleic acid self-assembly nanometer by adjusting the molecular structure of guanine peptide nucleic acid Ball shape control. 7. the sound field assistant preparation method of a kind of guanine peptide nucleic acid self-assembled nanosphere-based photonic crystal according to claim 1, is characterized in that: described guanine peptide nucleic acid uses guanine as side chain group, amide The amino acid-like structure with the bond as the molecular backbone, the groups used for the artificial synthesis of guanine peptide nucleic acid are diphenylmethoxycarbonyl (Bhoc), 9-fluorenylmethoxycarbonyl (Fmoc), glycine, aminoethyl, acetyl and guanine purine group. 8. the acoustic field assistant preparation method of a kind of guanine peptide nucleic acid self-assembled nanosphere-based photonic crystal according to claim 1 and 2, it is characterized in that: described guanine peptide nucleic acid self-assembled nanosphere is in the body acoustic wave transduction The device adopts the auxiliary arrangement of bulk acoustic wave standing wave field, and the shape of the arrangement is one-dimensional stripe, two-dimensional lattice shape or two-dimensional curve shape. 9. the sound field auxiliary preparation method of a kind of guanine peptide nucleic acid self-assembled nano-sphere-based photonic crystal according to claim 1 or 3, it is characterized in that: described guanine peptide nucleic acid self-assembled nano-sphere-based photonic crystal further adopts The following process is processed: 1) Weighing polyethylene glycol diacrylate with an average molecular weight of 200, adding a mixed photoinitiator TPO-L that accounts for 0.8% of the mass fraction of polyethylene glycol diacrylate to form a mixture; 2) fully mixing and defoaming the mixture using a planetary stirrer to prepare a photosensitive prepolymer; 3) Place the substrate with the guanine peptide nucleic acid self-assembled nanosphere-based photonic crystal on the spin coater, drop the photosensitive prepolymer evenly on the surface of the guanine peptide nucleic acid self-assembled nanosphere-based photonic crystal, and use spin coating The method forms a uniform film on the surface of the guanine peptide nucleic acid self-assembled nanosphere-based photonic crystal, and uses ultraviolet light curing to complete the encapsulation of the guanine peptide nucleic acid self-assembled nanosphere-based photonic crystal.

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