Nanofluid device with optical wavelength regulation and control function and application

Abstract

The invention discloses a nanofluid device with light wavelength regulation and control, which comprises a tubular channel and a built-in block, electrolyte solution exists in the tubular channel, the built-in block is a flexible high-molecular polymer doped with a light response substance, and the built-in block is arranged in the tubular channel and is in clearance fit with the tubular channel to form an annular nanochannel. The annular nano-channel generates an ionic current under the action of an external electric field, and the photoresponse substance generates a photothermal effect under the action of irradiation light, so that the built-in block expands to change the size of the annular nano-channel so as to change the size of the ionic current; the size of the annular nano channel can be dynamically changed according to the adjustment of the wavelength of emitted light and the optical power density, so that the transmission process of ions can be accurately controlled, and a new scheme is provided for the development of precise biosensors and microfluid equipment; and the method can be expanded to a nanofluid device array with photoresponse so as to be applied to the fields of artificial ion photoreceptors and the like.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of nanostructure, and particularly relates to a nano-fluid device with light wavelength regulation and application. BACKGROUND

[0002] Biological nanochannels play a crucial role in the body and precisely control the transmembrane transport of substances in complex life processes. Inspired by biological nanochannels, a large number of intelligent artificial solid-state nanopores and nanochannels have been constructed based on various materials and methods, especially light-responsive nanopores and nanochannels, which exhibit high spatiotemporal resolution through remote regulation of light signals, thereby realizing functions such as selective ion transport, gating, and rectification, similar to ion channels in the body. According to the structure and function of biological ion channels, light-controlled solid-state nanopores / nanochannels are mainly divided into two categories: one is a light-controlled ion channel with ion gating and rectification functions; the other is a light-driven ion pump with active regulation of ion transport characteristics. Currently, there are two main methods to construct biomimetic light-responsive nanopores / nanochannels. The first method is based on photosensitive materials, although a variety of materials have been used to study ion transport behavior, but this method is limited by the limitations of photosensitive materials and complex preparation processes. The second method uses light-responsive molecules (such as AZO, SP, porphyrin and its derivatives) to construct intelligent solid-state nanochannels.

[0003] In the study of light-controlled ion channels, the main focus is on controlling the opening and closing state of the channel through light signals. However, there is relatively little research on how to dynamically adjust these channels to achieve more precise control. Most light-responsive materials are only effective at specific wavelengths, which limits the ability to dynamically adjust the nanopore aperture by adjusting the wavelength of light. Despite the challenges, this regulation technology has great application potential in achieving fine control of material transport, providing new opportunities for the development of nanotechnology in the fields of materials science, sensor technology, information storage, and others. SUMMARY

[0004] The present application provides a nano-fluid device with light wavelength regulation and application to solve the problems in the prior art.

[0005] In order to achieve the above purpose, the technical scheme of the present application is as follows:

[0006] A nanofluidic device with wavelength-tunable light includes a tubular channel and an internal block. An electrolyte solution is contained in the tubular channel. The internal block is formed of a flexible polymer doped with a photoresponsive material. The internal block is disposed in the tubular channel and gap-fits with the tubular channel to form a ring-shaped nanochannel of electrolyte solution. The ring-shaped nanochannel generates an ion current under the action of an external electric field. The photoresponsive material generates a photothermal effect under the action of irradiation light, causing the internal block to expand and change the size of the ring-shaped nanochannel to change the magnitude of the ion current.

[0007] Optionally, the photoresponsive material is one of the carbonyl molecules, which produces different photothermal effects under irradiation light of different wavelengths. Preferably, the wavelength of the light is in the visible light band, including 460nm, 530nm, 660nm, etc.

[0008] Optionally, a multi-channel LED light source module can be used to achieve wavelength adjustment.

[0009] Optionally, the mass ratio of the flexible polymer to the carbon dragon molecule is 50 to 200:1.

[0010] Preferably, the type of carbon dragon molecule is thiopheneporphyrin-enebenzene carbon dragon molecule.

[0011] Optionally, the nanofluidic device is used for optical wavelength identification of the irradiated light.

[0012] Optionally, the irradiation light is pulsed light, and the ion current is pulsed current. Preferably, the duration of the light pulse is 1–10 s, the interval is 1–10 s, and the number of pulses is 1–40.

[0013] Optionally, the tubular channel is made of glass, and the flexible polymer includes at least one of polydimethylsiloxane, epoxy resin, and silicone; the inner wall surface and the surface of the built-in block of the tubular channel are hydrophilic to form a uniform annular nanochannel.

[0014] Optionally, the built-in block has the same cross-sectional shape as the tubular channel, and the annular width of the annular nanochannel ranges from 1 to 500 nm. Preferably, the cross-sectional shape includes a circle, a triangle, or a quadrilateral.

[0015] Optionally, the irradiation light includes ultraviolet light, near-infrared light, and visible light, and the current and conductivity of the nanofluidic device can be controlled by changing at least one of the light intensity, light wavelength, light pulse duration, and light pulse number.

[0016] Preferably, the optical power density of the irradiating light source is 10 mW / cm². 2 ~50mW / cm 2 More preferably, the optical power density of the light source can be 10 mW / cm².2 20mW / cm2 2 30mW / cm2 2 40mW / cm2 2 50mW / cm2 2 .

[0017] Preferably, the concentration of the electrolyte solution ranges from 0.1 mM to 1 M; further preferably, the concentration of the electrolyte solution can be 0.1 mM, 1 mM, 10 mM, 100 mM.

[0018] In an embodiment, the light-responsive substance powder is mixed with a flexible high polymer solution uniformly, poured into a mold cavity after vacuum degassing, cured at 50-70 DEG C for 3-5 hours, peeled off after curing, and cut into small pieces as built-in blocks; wherein the cross-sectional area of the tubular channel gradually changes along the axial direction, the mold cavity has the same structure as the tubular channel, and the surface of the mold cavity is hydrophobized; a section of the built-in block is selected and placed in the tubular channel, so that the built-in block and the tubular channel gap cooperate to form the annular nanochannel.

[0019] Further, in the axial direction of the tubular channel, the annular width of the annular channel is constant, i.e. the inner wall of the tubular channel is arranged in parallel with the outer wall of the built-in block.

[0020] A nanofluidic device array with light wavelength regulation includes a plurality of the above-mentioned nanofluidic devices with light response, wherein each nanofluidic device can be controlled individually.

[0021] Optionally, the nanofluidic device array with light response is applied to an artificial ion photoreceptor, and the nanofluidic device array includes at least two regions, and different illumination lights are used for the at least two regions to make the nanofluidic devices in different regions generate different ion currents.

[0022] The beneficial effects of the present application are:

[0023] 1) The flexible high polymer doped with light-responsive substances is combined with nanochannels to form annular nanochannels, the size of which can be dynamically adjusted according to the emitted light, and this dynamic adjustment of the size further affects the ion transport behavior in the annular nanochannels, so that the ion transport process can be accurately controlled, providing a new tool for the development of precise biosensors and microfluidic devices;

[0024] 2) By irradiating different light to specific areas of the nanofluidic device, we can adjust its structural state to achieve dynamic changes in ion current. When these nanofluidic devices are organized into an array, the design possibilities and diversity can be significantly improved. This regulation technology provides a powerful tool for constructing complex neural networks and simulating retinal function, showing great potential in biomedical engineering and intelligent system design;

[0025] 3) By adjusting the structure of the nanochannel, the ion conduction ability can be finely adjusted, and the conductivity can be significantly changed. Compared with electronic devices that rely on electron transmission, nanofluidic devices use ions as signal carriers, which have significant advantages. It is not affected by external magnetic field, so it performs better in stability and reliability; BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 The schematic diagram of the thienyl porphyrin-alkene benzocarbon molecular structure of the embodiment of the present application is shown.

[0027] Figure 2 The relationship between temperature and time of the PDMS in which the thienyl porphyrin-alkene benzocarbon molecular structure is compounded in embodiment 1 of the present application under different wavelength light irradiation is shown.

[0028] Figure 3 The schematic diagram of the preparation process of the ring-shaped nanochannel in embodiment 2 of the present application is shown.

[0029] Figure 4 The schematic diagram of the cross section of the ring-shaped nanochannel in embodiment 2 of the present application is shown.

[0030] Figure 5 The schematic diagram of the ion transmission system test device for adjusting the pore size of the ring-shaped nanochannel by controlling the wavelength of the light source in embodiment 2 of the present application is shown.

[0031] Figure 6 The I-T curve graph obtained by changing the pore size test using 450 nm wavelength light in embodiment 2 of the present application is shown.

[0032] Figure 7 The ring-shaped nanochannel conductance change curve graph under different light power density and wavelength light irradiation in embodiment 3 of the present application is shown.

[0033] Figure 8 The inhibitory postsynaptic current (IPSC) change graph of the ring-shaped nanochannel under different wavelength continuous light pulse light in embodiment 4 of the present application is shown.

[0034] Figure 9 The schematic diagram of assembling the nanofluidic device with wavelength regulation into an array in embodiment 5 is shown.

[0035] Figure 10 Schematic diagram of assembling the nanofluidic device with light wavelength regulation in Example 5 into an array for image display.

[0036] The figure mark: 1 is a glass tube, 2 is an internal block, 3 is an electrolyte solution, 4 is a working electrode, 5 is a reference electrode, 6 is a Keithley 6487 picoammeter, 7 is a computer terminal, 8 is a multi-channel LED light source, and 9 is an irradiation head. DETAILED DESCRIPTION

[0037] The present application will be further explained in connection with the accompanying drawings and specific examples. The drawings of the present application are only for easy understanding of the present application, and the specific proportions can be adjusted according to the design requirements.

[0038] The example develops a new type of composite PDMS material by compounding the thienyl porphyrin-alkenyl carbophenolene molecule with polydimethylsiloxane (PDMS). This material can exhibit unique photothermal effect under light of different wavelengths, thereby causing corresponding changes in the volume of PDMS. By combining this composite PDMS material with glass, a nanofluidic device based on nanochannel is prepared, the size of which can be dynamically adjusted according to the different wavelengths of light. This size adjustment further affects the ion transport behavior in the nanochannel, realizing precise control of ion transport. In a solution environment, the technology of regulating ion transport behavior by changing the wavelength of light is realized.

[0039] Example 1.

[0040] (1) Compound of thienyl porphyrin-alkenyl carbophenolene molecule and PDMS

[0041] Thienyl porphyrin-alkenyl carbophenolene molecule powder is added to the PDMS mixed solution in a ratio of 1:100, and the structure of the thienyl porphyrin-alkenyl carbophenolene molecule is as shown in Figure 1 The thienyl porphyrin-alkenyl carbophenolene molecule powder is uniformly dispersed in the PDMS matrix by ultrasonic dispersion, and then degassed for 5 min under vacuum. The glass tube containing the PDMS solution is placed in an oven for curing, the temperature is 60℃, and the time is 4h. After curing, cut into 2x2x2cm blocks.

[0042] (2) Photothermal test of composite thienyl porphyrin-alkenyl carbophenolene molecule PDMS

[0043] The block is placed under a multi-channel LED light source, and an infrared thermal imager is used to detect the surface temperature. Turn on the light source, the light power density is 30mW / cm 2, the wavelength is 460 nm, 530 nm, 660 nm, respectively, the relationship between the PDMS temperature and time is detected. Because the carbon dragon molecule in the PDMS produces a photo-thermal effect after absorbing light, and the photo-thermal effect of different wavelengths of light is different, the temperature of the PDMS gradually increases, and the temperature reaches equilibrium at about 300 s, as shown in Figure 2 .

[0044] Example 2

[0045] (1) Modification of the inner wall of the glass tube mold

[0046] The glass tube mold has a wall thickness of 1 mm, and the cross section of the tubular channel formed is circular with a maximum diameter of 4 mm, which gradually decreases along the axial direction, so that the inclination angle of the side wall relative to the axial direction is 20°. A "piranha" solution is prepared by mixing concentrated sulfuric acid and 30% hydrogen peroxide (volume ratio 3:1). The glass tube is placed in the solution and heated at 70°C for 30 minutes. After treatment, the glass tube is removed for cleaning, followed by silanization treatment and drying in a dry environment.

[0047] (2) Preparation of a nanofluidic device with light wavelength regulation

[0048] The preparation process is shown in Figure 3 . PDMS is mixed with a crosslinking agent (mass ratio 10:1), and thienyl porphyrin-ene benzocarbon dragon molecule powder is added and uniformly dispersed, with a mass ratio of 100:1. After vacuum degassing, it is filled into the hydrophobic treated glass tube mold, and after 4 hours of solidification at 60°C, it is peeled off and cut into small sections with a height of 2 mm. The same glass tube as the glass tube mold and the small sections are placed in a plasma cleaning machine for plasma surface activation treatment, with an activation power of 220 W and a treatment time of 4 min, to make the surface hydrophilic. Add 10 mM KCl solution as the electrolyte solution to the glass tube, select a small section to install into the glass tube as an embedded block, and accurately adjust its position. At this time, the inner wall of the glass tube 1 and the surface of the embedded block 2 form a size-adjustable annular nanochannel A, and the cross-sectional view is shown in Figure 4 . The I-V relationship in the channel is measured using a Keithley 6487 picoammeter, and the initial annular width of the annular nanochannel is adjusted to 1 μm.

[0049] (3) Stability test of single-color light regulated aperture

[0050] The nanofluidic device with light wavelength regulation is installed in the experimental device as shown in Figure 5 , and the electrolyte solution 3 on both sides of the embedded block 2 in the glass tube 1 is connected to the working electrode 4 and the reference electrode 5, respectively, and the electrode is an Ag / AgCl electrode. Figure 4, the I-T curve of the annular nanochannel A in 10 mM KCl solution was measured by these electrodes using a Keithley 6487 picoammeter 6 and displayed on a computer 7. A multi-channel LED light source 8 was used to act on the nanofluidic device, specifically by aligning its irradiation head 9 to the built-in block 2. A constant voltage of 1 V was applied across the nanochannel to measure the ionic current. After the current reached a steady state, the light source 8 was turned on, with a light power density of 30 mW / cm 2 , and a wavelength of 460 nm.

[0051] As the carbon dragon molecules in the PDMS material produce a photothermal effect after absorbing light energy, the volume of the built-in block 2 expands as the temperature of the PDMS rises, causing the annular width of the annular nanochannel A to gradually decrease, thereby reducing the ionic current. When the heat generated by the carbon dragon molecules and the heat dissipation reach a balance, the overall temperature of the PDMS stops rising, and the ionic current stabilizes. After the light source is turned off, as the temperature gradually decreases, the ionic current begins to rise. When the temperature returns to room temperature, the ionic current reaches a new steady state, and the experimental results are shown in Figure 6 .

[0052] Example 3.

[0053] The nanofluidic device and detection device are the same as in Example 2. A sweeping voltage of -1 to 1 V is applied across the annular nanochannel until the current reaches a steady state. Subsequently, the light source is turned on, with a light power density of 30 mW / cm 2 , and a wavelength of 450 nm. The ionic current is continuously monitored until it reaches a new steady state. Next, the wavelength of the light source is changed to 530 nm and 660 nm to observe the changes in the ionic current in the annular nanochannel due to the differences in the photothermal properties of the carbon dragon molecules at different wavelengths. As the carbon dragon molecules exhibit different photothermal effects under irradiation at different wavelengths, the ionic current in the nanochannel will exhibit different response characteristics at wavelengths of 450 nm, 530 nm, and 660 nm, and the experimental results are shown in Figure 7 .

[0054] The nanofluidic device is applied to the identification of light wavelengths, and the response characteristics of the ionic current in the annular nanochannel under irradiation by different light wavelengths are detected to create a correlation, so that the light wavelength can be identified by detecting the ionic current.

[0055] Example 4.

[0056] The nanofluidic device and detection device are the same as in Example 2. A sweeping voltage of -1 to 1 V is applied across the annular nanochannel to measure the ionic current of the annular nanochannel in 10 mM KCl solution. After the current stabilizes, the light source is turned on, with a light power density of 30 mW / cm 2, wavelength of 450 nm. The light source was pulsed, with each pulse lasting 5 seconds and being separated by 5 seconds, for a total of 20 pulses. After the test, the wavelength of the light source was adjusted to 530 nm and 660 nm to study how the photothermal properties of carbon dragon molecules affect the inhibitory postsynaptic current (IPSC) of the ring nanochannel under different wavelengths. It was observed that the signal gradually decreased and stabilized with the increase in the number of light pulses, showing obvious paired pulse facilitation (PPF) behavior. This observation helps to understand the influence of different wavelengths of light on the ion transport properties of the nanochannel, and the experimental results are shown in Figure 8 .

[0057] Example 5.

[0058] (1) Preparation of artificial ion photoreceptor array

[0059] A plurality of nanofluidic devices with multi-wavelength light response capability were assembled into a 6x18 array, and each nanofluidic device unit was independent and could be controlled individually. These units were designed as artificial ion photoreceptors, which could simulate the function of photoreceptors on the human retina and respond to different wavelengths of light. The structural diagram is shown in Figure 9 .

[0060] (2) Image display of artificial ion photoreceptor array

[0061] By applying three masks with specific shapes - petals, pistils, and flower stems, we can precisely control the light distribution on the nanofluidic device array. Each mask corresponds to a specific color of light: petals correspond to red light, pistils correspond to blue light, and flower stems correspond to green light. By adjusting the wavelength and intensity of the light, we can finely adjust the current generated by each unit.

[0062] Specifically, experimental data show that under the condition of 30-50 mW / cm 2 of light power density, the current change of the nanofluidic device under different color light sources has the following characteristics: under red light irradiation, the current change range is -42 to -55 nA; under green light irradiation, the current change range is -28 to -42 nA; and under blue light irradiation, the current change range is -24 to -28 nA. These current changes were recorded by a computer, and the current change values were mapped to one of the red, green, and blue color blocks by special software. By arranging and combining these color blocks in different positions, we can reproduce images on the computer screen, as shown in Figure 10 .

[0063] The above examples are only used to further illustrate the nanofluidic device with optical wavelength regulation and application of the present application, but the present application is not limited to the examples, and any simple modification, equivalent change and modification of the above examples according to the technical essence of the present application fall within the protection scope of the technical scheme of the present application.

Claims

1. A nanofluidic device with optical wavelength modulation, characterized in that: The device includes a tubular channel and an internal block. The tubular channel contains an electrolyte solution, and the internal block is formed of a flexible polymer doped with a photoresponsive material. The internal block is disposed in the tubular channel and interlocks with the tubular channel to form a ring-shaped nanochannel for the electrolyte solution. The ring-shaped nanochannel generates an ion current under the action of an external electric field, and the photoresponsive material generates a photothermal effect under the action of irradiation light, causing the internal block to expand and change the size of the ring-shaped nanochannel to change the magnitude of the ion current.

2. The nanofluidic device with optical wavelength modulation according to claim 1, characterized in that: The photoresponsive material is one of the carbon dragon molecules, which produces different photothermal effects under irradiation light of different wavelengths.

3. The photoresponsive nanofluidic device according to claim 2, characterized in that: The mass ratio of the flexible polymer to carbon dragon molecules is 50 to 200:

1.

4. The nanofluidic device with optical wavelength modulation according to claim 2, characterized in that: The nanofluidic device is used for optical wavelength identification of irradiated light.

5. The nanofluidic device with optical wavelength modulation according to claim 1, characterized in that: The irradiation light is pulsed light, and the ion current is pulsed current.

6. The nanofluidic device with optical wavelength modulation according to claim 1, characterized in that: The tubular channel is made of glass, and the flexible polymer includes at least one of polydimethylsiloxane, epoxy resin, and silicone; the inner wall surface and the surface of the built-in block of the tubular channel are hydrophilic.

7. The nanofluidic device with optical wavelength modulation according to claim 1, characterized in that: The built-in block has the same cross-sectional shape as the tubular channel, and the annular width of the annular nanochannel ranges from 1 to 500 nm.

8. The nanofluidic device with optical wavelength modulation according to claim 1, characterized in that: The irradiation light includes ultraviolet light, near-infrared light, and visible light. The current and conductivity of the nanofluidic device can be controlled by changing at least one of the following: light intensity, light wavelength, light pulse duration, and light pulse number.

9. A nanofluidic device array with optical wavelength modulation, characterized in that: It includes several nanofluidic devices with optical wavelength modulation as described in any one of claims 1 to 8, wherein each nanofluidic device can be controlled individually.

10. The nanofluidic device array with optical wavelength modulation according to claim 9, characterized in that: The nanofluidic device array with optical wavelength modulation is applied to an artificial ion photosensor. The nanofluidic device array includes at least two regions, and the at least two regions are illuminated with different light to generate different ion currents in the nanofluidic devices in different regions.

Images