Organic photoelectrochemical transistor sensor adopting photoelectric microelectrode as grid electrode and preparation method of organic photoelectrochemical transistor sensor
By using photoelectric microelectrode as gate in organic photoelectrochemical transistors and regulating drain current by using light induction, the problem of insufficient current in vivo detection in traditional photoelectrochemical technology is solved, high-sensitivity signal amplification and energy separation are achieved, and new in-situ detection technology is provided.
Patent Information
- Application Number
- CN202510344876.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-22
- Publication Date
- 2025-06-20
AI Technical Summary
Traditional photoelectrochemical technology is limited in live in situ detection, mainly because photoelectroactive materials require ultraviolet excitation, while the ultraviolet light of xenon lamps cannot penetrate the skin, and the current of traditional electrodes in live detection is small, limiting the precision of signal reading equipment.
An organic photoelectrochemical transistor (OPECT) sensor using a photoelectric microelectrode as the gate electrode can control the change of drain current by light-induced gate voltage to achieve signal amplification. The sensor combines the advantages of photoelectrochemical and organic electrochemical transistors, utilizing photoelectrodes as gates, no additional gate voltage is required, and the background signal is low.
Compared with traditional PEC sensors, the sensitivity of OPECT sensors is more than 100 times, achieving the advantage of separation of energy between excitation signals and detection signals. The detection can be achieved without high-precision instruments, providing a new solution for in-situ detection of living organisms.
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Figure CN120177595A_ABST
Abstract
Description
Technical Field
[0001] The present invention provides an organic optoelectrochemical transistor sensor using a photoelectric microelectrode as a gate and a preparation method thereof, relating to the field of optoelectronic sensors. Background Art
[0002] The photoelectrochemical (PEC) analysis method can convert optical signals into electrical signals, achieving the separation of the excitation source and the signal source, and has the characteristics of high sensitivity, low background signal, good spatio-temporal resolution, and miniaturization. The PEC sensor mainly consists of an excitation light source, a three-electrode system, an electrochemical workstation, and semiconductor materials, etc., and is suitable for the real-time and dynamic analysis of bioactive substances. However, currently, the optoelectrochemical technology is restricted in in vivo in-situ detection. The main problem is that most optoelectroactive materials require ultraviolet light excitation. The commonly used excitation source is a xenon lamp, but the xenon lamp has strong energy, and ultraviolet light cannot penetrate the skin and may cause harm to the skin.
[0003] Optical fibers have become a breakthrough new in-vivo monitoring tool due to their total reflection characteristics and are applied to PEC in-situ detection. By loading conductive media and other active materials on the surface of the optical fiber to construct a photoanode, it is not only possible to detect target substances at the micron scale, but also to avoid the problems of limited penetration depth and intensity attenuation of light in tissues. However, limited by the electrode area, its photocurrent signal is usually low, which poses high requirements on the precision of the signal readout device, thus restricting its practical application. Therefore, new means are urgently needed to enhance its sensitivity. In addition, the electrodes fabricated by traditional electrochemical (PEC) methods have a small current in in-vivo detection. Summary of the Invention
[0004] Aiming at the above problems, the organic optoelectrochemical transistor (OPECT) sensor combines the advantages of photoelectrochemistry and organic electrochemical transistor (OECT), uses a photoanode as the gate, and realizes signal amplification by regulating the change of the drain current through the photoinduced gate voltage. This signal can be read out only by using an ordinary electrochemical workstation, greatly reducing the equipment requirements. Compared with traditional PEC sensors, the sensitivity of the OPECT sensor is increased by more than 100 times, and it inherits the characteristics of high throughput, high sensitivity, and flexible structure of OECT. At the same time, it realizes the advantage of energy separation between the excitation signal and the detection signal, without the need to apply an additional gate voltage and with a low background signal. In addition, the sensing platform and the detection platform of the OPECT sensor are separated, reducing the interference of electroactive substances and providing a new solution for in-vivo in-situ detection.
[0005] In summary, by introducing optical fibers and organic optoelectrochemical transistor (OPECT) sensors, the present invention solves the limitations of traditional photoelectrochemical techniques in in vivo in-situ detection, provides a new technical means for the real-time and dynamic analysis of bioactive substances, and has broad application prospects. The technology provided by the present invention is used to solve the problem of small current in in vivo detection of optical fiber microelectrodes.
[0006] The present invention proposes an organic optoelectrochemical transistor sensor using a photoelectric microelectrode as a gate and a preparation method thereof, and the detailed content is as follows:
[0007] An organic optoelectrochemical transistor sensor using a photoelectric microelectrode as a gate, wherein the organic optoelectrochemical transistor sensor uses a photoelectric microelectrode as a gate; further, the organic optoelectrochemical transistor sensor using a photoelectric microelectrode as a gate uses a photovoltage induced by an external light source to regulate the channel current; wherein, the photoelectric microelectrode as a gate generates a photovoltage under the induction of an external light source through the photoelectric effect; wherein the photoelectric microelectrode includes an optical fiber and a photosensitive material; the organic optoelectrochemical transistor sensor includes interdigital electrodes and a channel material for modifying the interdigital electrodes.
[0008] Wherein, the organic optoelectrochemical transistor of the organic optoelectrochemical transistor sensor includes a gate - electrolyte - channel - source circuit and a source - channel - drain circuit; wherein, the photoelectric microelectrode as a gate generates a photovoltage under the induction of an external light source through the photoelectric effect, and when the organic optoelectrochemical transistor works, the gate voltage is all provided by the photovoltage, and the gate voltage does not require an external voltage source excitation; wherein, the connection mode between the photoelectric microelectrode as a gate and the source of the organic optoelectrochemical transistor sensor includes: the external wire of the organic optoelectrochemical transistor of the organic optoelectrochemical transistor sensor is wound around the conductive layer of the optical fiber of the photoelectric microelectrode as a gate.
[0009] Wherein, the optical fiber includes a plastic optical fiber, the plastic optical fiber is a multimode optical fiber, the core material of the plastic optical fiber uses modified polymethyl methacrylate (PMMA), and the cladding material of the plastic optical fiber is fluororesin; when the organic optoelectrochemical transistor sensor works, the wavelength range of the external light source passing through the plastic optical fiber is in the visible light wavelength range; the diameter of the plastic optical fiber is 250μm, the cladding thickness is 10μm, and the core diameter is 240μm.
[0010] Among them, the optical fiber includes a silica optical fiber, where the silica optical fiber is a multimode optical fiber. The core material of the silica optical fiber is silica glass (core diameter 105 μm), the cladding material of the silica optical fiber is a fluorine-doped silica glass cladding (core diameter 125 μm), and the coating layer of the silica optical fiber is acrylic resin (core diameter 245 μm). When the organic optoelectrochemical transistor sensor works, the wavelength range of the external light source passing through the silica optical fiber is in the near-ultraviolet and visible light wavelength ranges.
[0011] Among them, the interdigital electrode includes a single interdigital electrode, and the channel material for modifying the interdigital electrode includes poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid (PEDOT:PSS). The single interdigital electrode is modified by poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid (PEDOT:PSS), and the channel spacing of the single interdigital electrode is 10 μm.
[0012] Among them, the photosensitive material includes cuprous oxide.
[0013] In summary, the preparation method of the organic optoelectrochemical transistor sensor using the optoelectronic microelectrode as the gate includes fabricating the optoelectronic microelectrode, modifying the organic optoelectrochemical transistor, and constructing the organic optoelectrochemical transistor sensor.
[0014] Among them, fabricating the optoelectronic microelectrode includes the following steps: cutting the optical fiber into a fiber segment with a length of 9 - 10 cm, and polishing one end of the fiber segment with sandpaper, with the polishing length being 0.4 - 0.5 cm; ultrasonically cleaning the polished fiber segment with ethanol and water, drying the fiber segment after cleaning, sputtering a nickel coating and a gold coating on the dried fiber segment, where the nickel layer is about 5 nm and the gold layer is about 10 nm; then, dipping the conductive fiber deposited with the gold layer into a solution with uniformly dispersed cuprous oxide nanoparticles, drying it in a vacuum drying oven, and repeating the drying 3 times.
[0015] Among them, modifying the organic optoelectrochemical transistor includes the following steps: mixing 5 wt% ethylene glycol, 0.1 wt% dodecylbenzenesulfonic acid, 1 wt% 3-(2,3-epoxypropoxy)-propyltrimethoxysilane, and poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid (PEDOT:PSS), taking 5 μL of the mixed solution, dropping it on the channel surface of the interdigital electrode, and spinning off the excess solvent to obtain an interdigital electrode coated with poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid (PEDOT:PSS), and then reacting it in a tube furnace at 160 °C for 1 - 1.1 hours to cure the poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid (PEDOT:PSS); then fixing a copper wire on the surface of the interdigital electrode with conductive silver glue and thermally curing it with a baking lamp.
[0016] Among them, the method for constructing an organic optoelectrochemical transistor sensor includes: using an optical fiber microelectrode as the gate, and connecting the gate made of the optical fiber microelectrode to the source through a wire; then, through an electrochemical workstation, connecting the source to the counter electrode and the reference electrode, and connecting the drain to the working electrode, finally obtaining an organic optoelectrochemical transistor sensor using the optoelectronic microelectrode as the gate.
[0017] The present invention has the following advantages:
[0018] (1) The present invention uses an optical fiber microelectrode as the gate, realizing the combination of the optical fiber and the organic optoelectrochemical transistor for the first time, and amplifying the photocurrent of the optical fiber.
[0019] (2) The present invention optimizes the structure of the organic optoelectrochemical transistor, replaces the connection loop of the workstation with a wire, and only a single-channel workstation is required to detect the change of the channel current. Under illumination, the photovoltaic voltage generated by the gate directly acts on the channel without passing through the workstation. This connection method further amplifies the photocurrent signal.
[0020] (3) For the constructed sensor, its wiring method is more convenient, the size structure is more conducive to miniaturization, and detection can be achieved without high-precision instruments. Description of the Drawings
[0021] Figure 1 It is a schematic structural diagram of an organic optoelectrochemical transistor sensor using an optical fiber microelectrode as the gate in Example 1.
[0022] Figure 2 It is a photocurrent-time curve of a traditional optoelectrochemical system with an optical fiber as the working electrode in Example 1.
[0023] Figure 3 It is the change of the channel current of the transistor before and after the optimization of the structure in Example 1. Detailed Description of the Invention
[0024] In order to make the content described in the present invention easier to understand, the following further detailed description is made in conjunction with the embodiments of the present invention.
[0025] It should be noted that the following detailed description is illustrative and is intended to provide further description of the present application. Unless otherwise specified, all technical and scientific terms used in this specification have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present application belongs.
[0026] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular forms are also intended to include the plural forms. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they specify the presence of features, steps, operations, devices, components, and / or combinations thereof.
[0027] Example 1
[0028] This embodiment provides an organic optoelectrochemical transistor sensor using an optoelectronic microelectrode as a gate and a preparation method thereof.
[0029] (1) Fabrication of the fiber optic microelectrode
[0030] The fabrication of the optoelectronic microelectrode includes the following steps: Cut the optical fiber into fiber segments of 9 - 10 cm, and polish one end of the fiber segment with sandpaper, with the polishing length being 0.4 - 0.5 cm; Ultrasonically clean the polished fiber segment with ethanol and water. After cleaning the fiber segment, dry it, and perform metal sputtering on the dried fiber, with a nickel layer of about 5 nm and a gold layer of about 10 nm; Then, dip the conductive fiber with the deposited gold layer into a solution with uniformly dispersed cuprous oxide nanoparticles, and dry it in a vacuum drying oven. The drying is carried out in a vacuum drying oven at a drying temperature of 60 °C for a drying time of 10 min, and repeat the drying 3 times.
[0031] (2) Modification of the organic optoelectrochemical transistor
[0032] The organic optoelectrochemical transistor includes interdigitated electrodes and a channel material. Among them, the interdigitated electrodes include single interdigitated electrodes and multi - interdigitated electrodes. The channel material includes poly(3,4 - ethylenedioxythiophene) - polystyrenesulfonic acid.
[0033] Furthermore, both the single interdigitated electrode and the multi - interdigitated electrode are modified with poly(3,4 - ethylenedioxythiophene) - polystyrenesulfonic acid.
[0034] Furthermore, after the interdigitated electrodes are modified with poly(3,4 - ethylenedioxythiophene) - polystyrenesulfonic acid, the source and drain of the interdigitated electrodes are electrically connected.
[0035] The interdigital electrode used in this embodiment is a single interdigital electrode with a channel spacing of 10 μm. The modified organic optoelectrochemical transistor includes the following steps: Mix 5 wt% ethylene glycol, 0.1 wt% dodecylbenzenesulfonic acid, 1 wt% 3-(2,3-epoxypropoxy)propyltrimethoxysilane and poly(3,4-ethylenedioxythiophene)-polystyrenesulfonic acid (PEDOT:PSS). Take 5 μL of the mixed solution and drop it on the channel surface of the interdigital electrode, and spin-coat to remove the excess solvent, obtaining an interdigital electrode coated with poly(3,4-ethylenedioxythiophene)-polystyrenesulfonic acid (PEDOT:PSS). Then react at 160 °C in a tube furnace for 1 - 1.1 hours to cure the poly(3,4-ethylenedioxythiophene)-polystyrenesulfonic acid (PEDOT:PSS). After that, fix the copper wire on the surface of the interdigital electrode using conductive silver paste and cure it with a baking lamp.
[0036] The organic optoelectrochemical transistor uses a commercially available interdigital electrode. The interdigital electrode used is a single interdigital electrode with a channel spacing of 10 μm. Mix 5 wt% ethylene glycol, 0.1 wt% dodecylbenzenesulfonic acid, 1 wt% 3-(2,3-epoxypropoxy)propyltrimethoxysilane and PEDOT:PSS uniformly, and then spin-coat to uniformly coat the organic semiconductor on the channel surface. Specifically: Take 5 μL of the mixed solution, drop it on the channel surface, and spin-coat to remove the excess solvent.
[0037] (3) Construction of the sensor
[0038] Use the optical fiber microelectrode as the gate electrode and connect the gate electrode to the source electrode through a wire. Use an electrochemical workstation (such as Chenhua electrochemical workstation CHI760E). The electrochemical workstation has three electrode clips, namely the working electrode, the reference electrode, and the counter electrode. In addition, the two copper wires on the transistor do not distinguish between the source electrode and the drain electrode. Fix one end as the source electrode, and the other end is the drain electrode. Then, through the electrochemical workstation, connect the source electrode to the counter electrode and the reference electrode, and connect the drain electrode to the working electrode. Use the potentiostatic method and set the input voltage to -0.1 V to monitor the channel current. Apply a 470 nm laser irradiation to the optical fiber, which is equivalent to applying a voltage to the gate electrode. At this time, a corresponding current change occurs on the channel.
[0039] The sensor constructed in the present invention combines the optical fiber microelectrode and the organic electrochemical transistor for the first time. Compared with the traditional optoelectrochemical system, the organic optoelectrochemical transistor sensor using the optical fiber microelectrode as the gate electrode uses the photoinduced voltage generated by an external light source to regulate the channel current.
[0040] During actual application, such as Figure 1 、 Figure 2 、 Figure 3 shown, Figure 2It is the photocurrent-time curve of a traditional photoelectrochemical system with an optical fiber as the working electrode, and the current during operation is 50 nA. Figure 3 The current of a traditional organic photoelectrochemical transistor (OPECT) during operation is 4 μA.
[0041] The working current of the OPECT constructed by the present invention through optimizing the gate-source loop by directly connecting the gate with an optical fiber microelectrode to the source is 16 μA.
[0042] The organic photoelectrochemical transistor (OPECT) sensor combines the advantages of photoelectrochemistry and organic electrochemical transistor (OECT). It uses a photoelectrode as the gate and regulates the change of the drain current through light-induced gate voltage to achieve signal amplification. This signal can be read out only by using an ordinary electrochemical workstation, greatly reducing the equipment requirements. Compared with traditional PEC sensors, the sensitivity of OPECT sensors is increased by more than 100 times, and it inherits the characteristics of OECT such as high throughput, high sensitivity, and flexible structure. At the same time, it realizes the advantage of energy separation between the excitation signal and the detection signal, without the need to apply an additional gate voltage and with a low background signal.
[0043] The above are only the preferred embodiments of the present invention, and all equivalent changes made according to the scope of the patent application of the present invention shall fall within the scope covered by the present invention.
Claims
1. An organic photoelectrochemical transistor sensor using a photoelectric microelectrode as a gate, characterized in that: The organic photoelectrochemical transistor sensor adopts a photoelectric microelectrode as a gate; further, the organic photoelectrochemical transistor sensor adopting a photoelectric microelectrode as a gate regulates the channel current through the photovoltage induced by an external light source; wherein the photoelectric microelectrode serving as a gate generates a photovoltage under the induction of an external light source through the photoelectric effect; wherein the photoelectric microelectrode comprises an optical fiber and a photosensitive material; the organic photoelectrochemical transistor sensor comprises an interdigitated electrode and a channel material for modifying the interdigitated electrode.
2. The organic photoelectrochemical transistor sensor using a photoelectric microelectrode as a gate according to claim 1, characterized in that: The organic photoelectrochemical transistor of the organic photoelectrochemical transistor sensor comprises a gate-electrolyte-channel-source loop and a source-channel-drain loop; wherein the photoelectric microelectrode serving as the gate generates a photovoltage under the induction of an external light source through a photoelectric effect, and when the organic photoelectrochemical transistor is working, the gate voltage is entirely provided by the photovoltage, and the gate voltage does not require excitation from an external voltage source; wherein the photoelectric microelectrode serving as the gate and the source of the organic photoelectrochemical transistor sensor are connected in a manner that an external wire of the organic photoelectrochemical transistor of the organic photoelectrochemical transistor sensor is wound around a conductive layer of an optical fiber of the photoelectric microelectrode serving as the gate.
3. The organic photoelectrochemical transistor sensor using a photoelectric microelectrode as a gate according to claim 1, characterized in that: The optical fiber comprises a plastic optical fiber, wherein the plastic optical fiber is a multimode optical fiber, wherein the core material of the plastic optical fiber is modified polymethyl methacrylate, and the cladding material of the plastic optical fiber is fluororesin; when the organic photoelectrochemical transistor sensor is working, the wavelength range of the external light source passing through the plastic optical fiber is within the visible light wavelength range.
4. The organic photoelectrochemical transistor sensor using a photoelectric microelectrode as a gate according to claim 1, characterized in that: The optical fiber includes quartz optical fiber, wherein the quartz optical fiber is a multimode optical fiber, wherein the core material of the quartz optical fiber is quartz glass, the cladding material of the quartz optical fiber is a fluorine-doped quartz glass cladding, and the coating layer of the quartz optical fiber is acrylic resin; when the organic photoelectrochemical transistor sensor is working, the wavelength range of the external light source passing through the quartz optical fiber is in the near-ultraviolet light and visible light wavelength range.
5. The organic photoelectrochemical transistor sensor using a photoelectric microelectrode as a gate according to claim 1, characterized in that: The interdigital electrode comprises a single interdigital electrode, and the channel material used to modify the interdigital electrode comprises poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid; wherein the single interdigital electrode is modified with poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid.
6. The organic photoelectrochemical transistor sensor using a photoelectric microelectrode as a gate according to claim 1, characterized in that: The photosensitive material includes cuprous oxide.
7. A method for preparing an organic photoelectrochemical transistor sensor using a photoelectric microelectrode as a gate, which is applied to prepare an organic photoelectrochemical transistor sensor using a photoelectric microelectrode as a gate as claimed in any one of claims 1 to 6, characterized in that: The preparation method of an organic photoelectrochemical transistor sensor using a photoelectric microelectrode as a gate comprises making a photoelectric microelectrode, modifying an organic photoelectrochemical transistor and constructing an organic photoelectrochemical transistor sensor.
8. The method for preparing an organic photoelectrochemical transistor sensor using a photoelectric microelectrode as a gate according to claim 7, characterized in that: The preparation of the photoelectric microelectrode includes the following steps: cutting the optical fiber into 9-10 cm optical fiber segments, polishing one end of the optical fiber segment with sandpaper, ultrasonically cleaning the polished optical fiber segment with ethanol and water, drying the optical fiber segment after cleaning, and sputtering a nickel coating and a gold coating on the dried optical fiber; then, dipping the conductive optical fiber with the gold layer deposited thereon into a solution of cuprous oxide nanoparticles and drying it in a vacuum drying oven.
9. The method for preparing an organic photoelectrochemical transistor sensor using a photoelectric microelectrode as a gate according to claim 7, characterized in that: The modified organic photoelectrochemical transistor includes the following contents: ethylene glycol, dodecylbenzenesulfonic acid, 3-(2,3-epoxypropoxy)-propyltrimethoxysilane and poly(3,4-ethylenedioxythiophene)-polystyrenesulfonic acid are mixed, 5 μL of the mixed solution is dripped on the channel surface of the interdigitated electrode to obtain the interdigitated electrode coated with poly(3,4-ethylenedioxythiophene)-polystyrenesulfonic acid, and then the interdigitated electrode coated with poly(3,4-ethylenedioxythiophene)-polystyrenesulfonic acid is reacted in a tube furnace to solidify the poly(3,4-ethylenedioxythiophene)-polystyrenesulfonic acid; then the copper wire is fixed on the surface of the interdigitated electrode with conductive silver glue, and the conductive silver glue is solidified with a baking lamp.
10. The method for preparing an organic photoelectrochemical transistor sensor using a photoelectric microelectrode as a gate according to claim 7, characterized in that: The method for constructing an organic photoelectrochemical transistor sensor includes: using an optical fiber microelectrode as a gate, and connecting the gate made of the optical fiber microelectrode to the source through a wire; then, through an electrochemical workstation, connecting the source to a counter electrode and a reference electrode, and connecting the drain to a working electrode, and finally obtaining an organic photoelectrochemical transistor sensor using a photoelectric microelectrode as a gate.