KR20110021022A - Nanomechanical sensor using nanotube cantilever with fluorescent nanoparticles and method thereof - Google Patents

Abstract

PURPOSE: A nanomechanical sensor using a nanotube cantilever with fluorescent nanoparticles is provided to measure physical transformation of nano-scale using a nanotube cantilever with fluorescent nanoparticles. CONSTITUTION: A nanomechanical sensor comprises a nanotube cantilever(10) with fluorescent nanoparticles, an optical apparatus(30), a control unit(40), and an output unit(50). The nanotube cantilever with fluorescent nanoparticles consists of microelectrodes, carbon nanotubes, and fluorescent nanoparticles. The optical apparatus includes a light source, an exciter filter, a dichroic mirror, and a photosensor.

Description

Nano-mechanical sensor using fluorescent nanoparticle-coupled nanotube cantilever and its sensing method {NANOMECHANICAL SENSOR USING NANOTUBE CANTILEVER WITH FLUORESCENT NANOPARTICLES AND METHOD THEREOF}

The present invention is a nano-manipulation technology for the individual manipulation of the micro sample and high resolution nano-measuring technology of the displacement according to the operation and the device capable of detecting the ultra-fine force applied to the sample at this time. More specifically, the bending displacement of the nanotubes is measured by attaching the fluorescent particles to the ends of the multi-walled carbon nanotube cantilever for ultra-fine force measurement and monitoring the positional change of the fluorescent particles using an optical system for fluorescence measurement. The present invention relates to a nanomechanical sensor using a fluorescent nanoparticle-coupled nanotube cantilever that can measure the force applied from the spring constant and bending displacement of the manufactured nanotube, and a sensing method thereof.

Cantilevered micro / nano sensors use the cantilever's static displacement to measure microscopic forces, such as nano and pico Newtons, and trace mass, gas particles, And it has been widely used in the field of measuring the concentration of biological material. Cantilever sensors manufactured using micro electro-mechanical systems (MEMS) since 2000 have been in the spotlight in the form of high-sensitivity measurement sensors, and have improved resolution by manufacturing sensors of various materials, sizes and shapes. The research to be continued continues until recently.

In order to improve the measurement resolution of the cantilever sensor, it is required to develop a sensor having a high resonance frequency and a small spring constant. The recent research on cantilever sensor research shows that the fabrication of the sensor in the form of a nano-cantilever with a nanometer thickness from the initial micro cantilever is made, and the measurement resolution is improved as a result.

FIG. 1A is a diagram schematically illustrating a configuration of a micro cantilever based on a conventional MEMS technology. Until now, the nano cantilever is a micro cantilever 11, as shown in FIG. 1A, and is made through the fabrication of a top-down method using micro-machining technology. And a micrometer level having a length L1 of 20 μm to 50 μm, and only a thickness t of 100 nm is not a true “nano cantilever”.

Figure 1b is a schematic diagram showing the configuration of a nanotube-based nano cantilever presented as a configuration of an embodiment according to the present invention. Recently, as shown in FIG. 1B, a nano cantilever 12 using nanomaterials such as nanotubes and nanowires having a diameter d of 200 nm or less and a length L2 of 20 μm to 50 μm and Research to evaluate characteristics has been published. According to the research results, the nano-tube cantilever of the bottom-up fabrication method using nanotubes and nanowires, which are one-dimensional nanostructures, has a higher measurement resolution than the conventional nano cantilevers.

In order to improve the measurement resolution of the nanotube cantilever type sensor, development of a sensor having a high resonant frequency and a small spring constant is required, but despite the excellent mechanical properties of the nanotube cantilever as a high resolution sensor, There was no way to measure static and dynamic displacements with several nanometer resolution.

In addition, since most of the displacement measurement of the nanotube is made through an electron microscope image in a vacuum environment, it is urgent to develop a nanomechanical sensor capable of measuring displacement in an air and liquid environment for application to a biological sample.

Accordingly, the present invention has been made in accordance with the above needs, the first object of the present invention is to provide a nano-mechanical sensor using a carbon nanotube-based nanotube cantilever capable of measuring static and dynamic displacement in air and liquid environments There is.

In addition, a second object of the present invention is to provide a nanomechanical sensor using a fluorescent nanoparticle-coupled nanotube cantilever that can measure nanometer-level physical deformation by using a nanotube cantilever attached with fluorescent nanoparticles.

In addition, a third object of the present invention is to provide a method for sensing a nanomechanical sensor using a fluorescent nanoparticle-coupled nanotube cantilever that can obtain the bending displacement of carbon nanotubes required for physical quantity calculation through the fluorescence measurement of fluorescent nanoparticles. There is.

The object of the present invention as described above, one end of the carbon nanotube 110 and the carbon nanotube 110 of a predetermined size attached to one end of the micro electrode 100, the micro electrode 100 that can apply a predetermined voltage. A fluorescent nanoparticle-coupled nanotube cantilever 10 composed of fluorescent nanoparticles 120 attached thereto; A light source 300 for supplying predetermined light to the fluorescent nanoparticles 120, an excitation filter 310 for transmitting only the excitation light in a wavelength band positioned in the irradiation direction of the light to excite the fluorescent nanoparticles 120, and the fluorescent nanoparticles 120 A fluorescent optical device 30 composed of a dichroic mirror 320 for transmitting only the emitted fluorescence as a result of absorbing the excitation light and reflecting the excitation light, and a photosensor 330 for detecting the transmitted fluorescence; Control means (40) for receiving the fluorescence information detected from the photosensor (330) to derive the dynamic displacement or static displacement of the fluorescent nanoparticle (120), and calculate a predetermined physical quantity based on the dynamic displacement or static displacement; And output means 50 for outputting physical quantity information corresponding to the physical quantity inputted from the control means 40, which can be achieved by providing a nanomechanical sensor using a fluorescent nanoparticle-coupled nanotube cantilever. have.

The carbon nanotubes 110 preferably have a length to diameter ratio of 50: 1 to 1000: 1.

In addition, the carbon nanotubes 110 are preferably multi-walled carbon nanotubes that can be observed under an optical microscope.

And the carbon nanotubes 110 is preferably formed with a carboxyl group 112 at the end.

The fluorescent nanoparticles 120 are fluorescent nanoparticles 300 having functionalized chemical groups of any one of straptrevidin, biotin, and amine groups to enable specific binding to biomolecules. Is preferable.

The fluorescent nanoparticle 120 may be any one of several nanometer quantum dots, several tens of nanometer fluorescent dyes, and several hundred nanometer single fluorescent nanoparticles.

The photosensor 330 may be a charge coupled device (CCD) or a four-segment photosensor.

The fluorescent optical device 30 preferably further includes a first lens 305 for collimating the light supplied from the light source 300 between the light source 300 and the excitation filter 310.

The fluorescence optical device 30 includes: a second lens 315 for focusing excitation light or emitted fluorescence reflected between the dichroic mirror 320 and the fluorescent nanoparticles 120; And a third lens 325 for forming fluorescence between the dichroic mirror 320 and the photosensor 330.

The fluorescence optical device 30 preferably further includes an emission filter 340 for extracting fluorescence between the dichroic mirror 320 and the photosensor 330.

The nano-mechanical sensor using the fluorescent nanoparticle-coupled nanotube cantilever may further include a nano stage 20 mounted with the fluorescent nanoparticle-coupled nanotube cantilever 10 and capable of moving a predetermined distance.

In addition, the nano stage 20 may be driven by three-axis control.

On the other hand, an object of the present invention as another category, the step of binding a predetermined material to the carbon nanotubes 110 to which the fluorescent nanoparticles 120 are attached at one end (S100); Acquiring fluorescence information from the photosensor 330 embedded in the fluorescence optical device 30 in response to the bending displacement of the carbon nanotubes 110 (S110); The control means 40 connected to the fluorescence optical device 30 measures the bending displacement of the fluorescent nanoparticles 110 from the fluorescence information to measure the static displacement or the dynamic displacement of the fluorescent nanoparticles 120 (S120); The control means 40 calculating a physical quantity of the combined material through a static displacement or a dynamic displacement of the fluorescent nanoparticle 120 (S130); And outputting the physical quantity information corresponding to the calculated physical quantity (S140) by the output means 50. Achieving by providing a sensing method of a nanomechanical sensor using fluorescent nanoparticle-coupled carbon nanotubes, comprising: Can be.

The substance to be bound is preferably a single biomolecule which is any one of deoxyribonucleic acid (DNA), protein, protein, ligand and receptor.

The derived physical quantity may be any one of the binding force between heterogeneous biomolecules and the single protein folding force through the static displacement measurement of the carbon nanotube 110.

The substance to be bound may be a gas molecule.

The derived physical quantity may be a binding concentration of gas molecules according to a change in natural frequency of the carbon nanotubes 110.

According to one preferred embodiment of the present invention, since the static and dynamic displacement measurement in the air and liquid environment is possible, the nano-mechanical sensor using the fluorescent nanoparticle-coupled nanotube cantilever is a high sensitivity sensor in the field of bio and electrochemical sensors There is an effect available.

It is useful for analyzing nanoscale mechanical / chemical / biological systems because it is possible to characterize individual samples of samples rather than the existing ensemble and to observe the relevant reactions in real time.

In addition, the nanometer size of carbon nanotubes is comparable to those of biomolecules (eg, DNA, proteins, etc.). have.

Depending on the size of the sample, the area of the related force changes.For nanomaterials represented by biomolecules such as DNA and proteins, nanoparticles, and new nanomaterials such as nanowires, nano or pico-Newton (nN or pN) sizes are very fine. Force measurement is necessary. The present invention can be a useful tool for force spectroscopy for extracting structural and functional properties of samples and extracting related physical quantities such as binding forces between different samples by manipulating the target sample and measuring the ultra-fine force generated at this time. have.

In addition, due to the high size and small size of nanotubes in biomolecule-related force measurement, the measurement results are not only improved compared to conventional nuclear atomic force microscopes, but also exceed the measurement resolution of 200 nm, which is the limit of measurement of optical microscopes. As a technology, it can be used as a tool for evaluating nanomechanical properties of newly developed nanomaterials.

<Nano machine sensor Example >

Figure 2a is a block diagram showing the configuration of an embodiment according to the present invention, Figure 2b is a view showing the interaction between the fluorescent nanoparticles and the fluorescent optical device 30 of the configuration of one embodiment according to the present invention.

As shown in Figures 2a and 2b, one embodiment of the nanomechanical sensor of the present invention is a fluorescent nanoparticle-coupled nanotube cantilever 10, fluorescent optics 30, control means 40 and output means 50 It is composed of In addition, the nano stage 20 may be an additional configuration. Briefly explaining the connection or action between them, when the fluorescent nanoparticle-coupled nanotube cantilever 10 is irradiated with excitation light and emits fluorescence, the photosensor 330 detects the fluorescence and the control means 40 measures the fluorescence. Analyze through to calculate a predetermined physical quantity. The physical quantity information corresponding to the physical quantity is received by the output means 50 and output in a predetermined form.

2A and 2B, a detailed configuration of the fluorescent nanoparticle-coupled nanotube cantilever 10 is attached to one end of the micro electrode 100 and the micro electrode 100 to which a predetermined voltage can be applied. It consists of carbon nanotubes (110) of size and fluorescent nanoparticles (120) attached to one end of the carbon nanotubes (110).

The micro electrode 100 is connected to a power supply and is configured to apply a predetermined voltage in the use of the fluorescent nanoparticle-coupled nanotube cantilever 10 (eg, dynamic displacement and static displacement measurement). do.

The carbon nanotube 110 is a multi-walled nanotube (MWNT) whose size can be observed in an optical microscope, and a mechanical bonding method using an adhesive such as carbon tape under an optical microscope, and It is attached to the end of the micro electrode 100 by the electrical bonding method. After the initial adhesion, the carbon is irradiated to the bonding site in the electron microscope environment to enhance the adhesion between the carbon nanotubes 200 and the micro electrode 100, so that the amorphous carbon material inside the electron microscope is deposited on the bonding site. The nanotubes 110 are fixed.

In addition, the carbon nanotubes 110 need to be configured to have a spring constant of 0.001 to 0.01 N / m so as to be suitable for detecting the fine force of a predetermined material to be bonded, for this purpose, the length-to-diameter ratio of the carbon nanotubes 200 is at least 50. More than one is used, and a carboxyl group (-COOH) is formed at the end to attach the fluorescent nanoparticles 300 to be described later.

Fluorescent nanoparticles 120 is a configuration for obtaining fluorescence information corresponding to the bending displacement of the carbon nanotubes 110, quantum dots (Quantum Dots) of several nanometers, fluorescent dyes (Dye) of several nanometers and hundreds of nanometers Single fluorescent nanoparticles (Nanoparticle) of the size is possible configuration. In addition, the fluorescent nanoparticle 300 is a fluorescent nanoparticle having a functionalized chemical group of any one of straptevidin (Streptavidin), biotin (Biotin) and an amine group (-Amine group) to enable specific binding to the biomolecule It is preferable that it is (120).

In the embodiment according to the present invention, polystyrene fluorescent nanoparticles (120, F8764, Invitrogen Inc.) having a spherical shape having a diameter of 200 nm was selected, and the polystyrene nanoparticles used were amine groups around them. There may be attached to the carbon nanotubes 110 through a hydrogen bond with the carboxyl group (-COOH) of the carbon nanotubes (110). Since the fluorescent nanoparticle-coupled nanotube cantilever 10 uses an inherent mechanical property of the carbon nanotubes 110, the fluorescent nanoparticles 120 need to be bonded only to the ends of the carbon nanotubes 110. .

The fluorescent optical device 30 includes a light source 300 for supplying excitation light to the fluorescent nanoparticles 120 and an excitation filter that transmits only light in a wavelength region positioned in the irradiation direction of the excitation light to excite the fluorescent nanoparticles 120 ( 310, a dichroic mirror 320 that transmits only fluorescence emitted from the excited fluorescent nanoparticles 120 and reflects light from a light source, and a photo sensor 330 that detects fluorescence on the image surface 332. In addition, the first lens 305, the second lens 315, and the third lens 325 may further include the configuration.

The light source 300 is to excite the fluorescent nanoparticles, and in the present embodiment, light including a wavelength near 490 nm, which is an absorption wavelength band of the fluorescent nanoparticles, is irradiated, and the excitation filter 310 has a wavelength of 470 to 495 nm. It was used to transmit light in the wavelength band. The excitation filter 310 is positioned between the light source 300 and the dichroic mirror 320 in the direction of light travel.

The dichroic mirror 320 is configured to filter excitation light incident from the light source 300 and transmit fluorescence to the photo sensor 330. In this embodiment, the dichroic mirror 320 uses a wavelength of 505 nm. Here, the emission filter 340 is used to transmit only light in the wavelength band of 510 to 520 nm to the photosensor 330.

The photo sensor 330 may use a photodiode, a photomultiplier tube (PMT), a charge coupled device (CCD) camera, or the like. The photosensor 330 includes a fluorescence image surface 332 in which fluorescence is imaged, and the fluorescence image surface 332 in this embodiment has a pixel size of 4.65 × 4.65 μm ² .

In addition, the first lens 305 between the light source 300 and the excitation filter for fluorescence measurement, and the second lens 315 for condensing the fluorescence emitted between the dichroic mirror 320 and the fluorescent nanoparticles 120. In addition, a third lens 325 may be further included between the dichroic mirror 320 and the photosensor 330 to configure the fluorescent optical device 30.

The control means 40 is configured to derive the dynamic displacement or static displacement of the fluorescent nanoparticles 120 by receiving the fluorescence information detected from the photosensor 330, and based on the dynamic displacement or static displacement, Example: ultra-fine force such as nano and pico Newton, ultra-small mass, gas particles, and concentration of biological material) is calculated and output to the output means 50.

The output means 50 is a component for outputting physical quantity information corresponding to the physical quantity received from the control means 40, and it is preferable to include a video display device and to visually output various numerical values or graphs.

The nano stage 20 is attached to the fluorescent nanoparticle-coupled nanotube cantilever 10 and configured to perform fine driving. To this end, a capacitive sensor (not shown) is provided therein, and a three-axis control device may be used to drive in various directions.

< Sensing  Way of Example >

3 is a flowchart illustrating a process of a sensing method according to an embodiment of the present invention. A method of sensing a nanomechanical sensor using a fluorescent nanoparticle-coupled nanotube cantilever according to the present invention will be described with reference to FIG. 3.

First, a predetermined material is bonded to the carbon nanotubes 110 to which the fluorescent nanoparticles 120 are attached at one end (S100). Here, the predetermined material binding step (S100) refers to binding to a predetermined material (eg, DNA, protein, gas molecules, etc.) to measure a physical quantity (eg, various physical quantities such as force, mass, and gas concentration).

Next, in response to the bending displacement of the carbon nanotubes 110, fluorescence information is obtained from the photosensor 330 embedded in the fluorescence optical device 30 (S110).

Here, in the fluorescence information acquisition process (S110), the excitation light irradiated from the light source 300 of the fluorescent optical device 30 is irradiated onto the fluorescent nanoparticles 120 attached to the ends of the carbon nanotubes 110. The fluorescent nanoparticles 120 emit light. Subsequently, fluorescence is detected on the fluorescence image surface 332 of the photosensor 330 to obtain fluorescence information.

Here, the photosensor 330 may use a photodiode, a photomultiplier tube, a charge coupled device, a camera and the like.

Next, the control means 40 connected to the fluorescent optical device 30 compares the central position of the fluorescent nanoparticles 110 from the fluorescence information to measure the static displacement or the dynamic displacement of the fluorescent nanoparticles 120 (S120).

Next, the control means 40 calculates the physical quantity of the combined material through the static displacement or the dynamic displacement of the fluorescent nanoparticles 120 (S130).

In order to calculate the physical quantity of the bound material, first, the spring constant of the carbon nanotube cantilever is derived as k. In this case, if the length of the carbon nanotubes used is L, the moment of inertia is I, and the Young's modulus is E, it can be expressed as Equation 1 below. In general, multi-walled carbon nanotubes (MWNT) ) Is less than or equal to 0.001 N / m (1.0 pN / nm).

Then, the bending displacement of the nanotubes is measured through the displacement of the fluorescent nanoparticles 120 attached to the ends of the carbon nanotubes 110 through the fluorescence optical device 30. The force F applied to (110) can be expressed by Hooke's Law as follows.

Finally, the output means 50 outputs the physical quantity information corresponding to the calculated physical quantity in various numerical or graph forms (S140).

The substance to be bound may be a single biomolecule which is any one of a deoxyribonucleic acid (DNA), a protein, a ligand, and a receptor, and the physical quantity derived in this case is the carbon nanotube 110. Static displacement measurement results in the microscopic force of either the binding force between the heterologous biomolecules or the single protein folding force.

In addition, the substance to be bonded may be a gas molecule, and the physical quantity derived in this case may be a gas molecule according to a natural frequency change of the fluorescent nanoparticle-coupled carbon nanotube 10 based on the dynamic displacement measurement of the carbon nanotube 110. Is the binding concentration of.

Figure 4a and 4b is a view showing a fluorescence image for measuring the dynamic displacement of the carbon nanotubes of the sensing method according to the invention, Figure 4c is a natural frequency used for the dynamic displacement measurement as a process of the sensing method according to the present invention In order to obtain, a diagram showing a dynamic vibration displacement graph according to the frequency of carbon nanotubes.

As shown in FIGS. 4A and 4B, as a result of performing a process of sensing a nanomechanical sensor using the fluorescent nanoparticle-coupled nanotube cantilever 10, a change in the frequency of the supply power (AC power) is performed. As a result, the dynamic bending displacement of the nanotube cantilever varies, and thus the fluorescence images 338a and 338b vary.

In addition, as shown in Figures 4a and 4b, the fluorescent nanoparticle-coupled nanotube cantilever has a natural frequency according to the size of the carbon nanotubes 110, the dynamic of the fluorescent nanoparticle-coupled nanotube cantilever (10) The resonance frequency may be derived from the fluorescent images 338a and 338b corresponding to the vibration displacements 334a and 334b. In addition, the physical quantity of the material may be derived, and a graph as shown in FIG. 4C may be represented through a Gaussian approximation by obtaining a plurality of fluorescent images.

As shown in FIG. 4C, the resonance frequency of the carbon nanotubes 110 may be obtained at the maximum vibration displacement 334c.

Figure 5a is a simplified view showing an experimental example for showing the linearity of the static displacement measurement in the sensing method according to the present invention, Figure 5b is a diagram showing a static displacement graph with respect to the applied voltage as a result of performing the experimental example shown in FIG. .

As shown in FIG. 5A, it can be seen that the carbon nanotube 110 has a bending displacement due to the electrostatic force formed between the micro electrode 100 and the counter electrode 102 when a DC power source having a predetermined size is applied. In addition, FIG. 5B shows that such a deflection displacement is proportional to the applied voltage, thereby enabling sensing of the nanomechanical sensor.

As an example of measuring the static displacement, the fluorescence intensity of the fluorescence images 338a and 338b taken on the image plane of the photosensor 330 through the fluorescence optical device 30 follows a Gaussian distribution. After defining the highest intensity point of the Gaussian distribution as the center of the fluorescent nanoparticles 120, the displacement of the fluorescent nanoparticles 300 may be measured by comparing the central positions of the fluorescent nanoparticles 300 in each image. This process is described in Hyojun Park et. al., Review of Scientific Instruments, 80, 053703 (2009), detailed descriptions are omitted here.

6 is a view showing a method of calculating the bending displacement of carbon nanotubes using a four-segment photosensor in the sensing method according to the present invention. As shown in FIG. 6, in the case of using the four-segment photosensor, the number of photons entering each four-segment photosensor varies according to the position of the fluorescent nanoparticles 120. At this time, the displacement (x, y) of the cantilever can be obtained from the following relationship, respectively. Where x is in one direction and y is in the direction perpendicular to x. And A1, A2, A3, and A4 denote the number of photons that reach each plane represented by four divisions of the fluorescent image plane 333 on which the virtual fluorescent image 339 is formed.

The four-segment photoelectric sensor may be a four-segment photodiode, a four-segment photoelectron multiplier and a charge coupled device camera.

< Example  For error measurement Experimental Example >

7A and 7B are driving stages comparing the measured displacements of the fluorescent nanoparticle-coupled nanotube cantilevers and the actual displacements measured by the capacitive sensor embedded in the nano-stage as an embodiment according to the present invention. Fig. 7C is a diagram showing a square wave displacement graph and a step displacement graph of a driving stage, and Fig. 7C is a diagram showing a displacement error histogram showing the accuracy of fluorescence measurement based on Figs. 7A and 7B.

As shown in Figs. 7A and 7B, the measurement displacement and the actual displacement were obtained as an accuracy of ± 6.83 nm when the error was analyzed using the unit displacement of 50 nm as the target displacement. This is confirmed through a displacement error histogram showing the accuracy of the fluorescence measurement of FIG. 6C.

Here, the capacitive sensor (not shown) is a sensor that can be measured with an accuracy of ± 2.7 nm, and the driving displacement was measured and compared through the fluorescence image analysis for the step driving and the stair driving. It can be seen from the fluorescence measurement that the displacement of the nanotubes with a resolution of about 10nm can be measured. This exceeds the measurement resolution (~ 200nm) of conventional optical microscopes.

는 아래의 [수학식 5]로 예측 가능하다.Therefore, force resolution measurable with this nanomechanical sensor

Is predictable by Equation 5 below.

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, It will be understood that the invention may be practiced. Therefore, the embodiments described above are to be understood as illustrative and not restrictive in all aspects. In addition, the scope of the present invention is indicated by the appended claims rather than the detailed description above. Also, it is to be construed that all changes or modifications derived from the meaning and scope of the claims and their equivalent concepts are included in the scope of the present invention.

Figure 1a is a configuration of a micro-cantilever based on the conventional Micro Electro-Mechanical Systems (MEMS) technology, Figure 1b is a schematic view showing the configuration of a nanotube-based nanotube cantilever presented as a configuration of an embodiment according to the present invention,

Figure 2a is a block diagram showing the configuration of an embodiment according to the present invention,

Figure 2b is a view showing the interaction between the fluorescent nanoparticles and the fluorescent optical device 30 of the configuration of one embodiment according to the present invention,

3 is a flowchart illustrating a process of a sensing method according to an embodiment of the present invention;

4a and 4b is a view showing a fluorescence image for measuring the dynamic displacement of carbon nanotubes of the sensing method according to the present invention,

Figure 4c is a diagram showing a dynamic vibration displacement graph according to the frequency of the carbon nanotubes to obtain the natural frequency used in the dynamic displacement measurement as an embodiment according to the present invention,

Figure 5a is a simplified view showing an experimental example for showing the linearity of the static displacement measurement of the sensing method according to the present invention,

FIG. 5B is a diagram showing a static displacement graph with respect to an applied voltage as a result of performing the experimental example shown in FIG. 5A; FIG.

6 is a view illustrating a method of calculating bending displacement of carbon nanotubes through a fluorescence image imaged by a four-segment photo sensor in a sensing method according to the present invention;

7A and 7B are measurement displacements according to the driving of fluorescent nanoparticle-coupled nanotube cantilevers as an embodiment according to the present invention, and actual displacements measured through capacitive gap sensors embedded in the nano-stage. Shows a step displacement graph of the driving stage and a stage displacement graph of the driving stage,

FIG. 7C is a diagram showing a displacement error histogram showing the accuracy of fluorescence measurement based on FIGS. 7A and 7B.

Description of the Related Art [0002]

L1: length of micro cantilever, L2: length of carbon nanotube

d: diameter of carbon nanotube, w: width of micro cantilever, t: thickness of micro cantilever

10: fluorescent nanoparticle-bound nanotube cantilever

11: micro cantilever

12: nano cantilever

20: nano stage

30: fluorescent optics

40: control means

50: output means

100: micro electrode

102: counter electrode

110: carbon nanotube

112: carboxyl group

120: fluorescent nanoparticles

300: light source

305: first lens

310: excitation filter

315: second lens

320: unusual mirror

325: third lens

330: photosensor

332, 333: fluorescent image plane

334a, 334b: dynamic displacement

334c: maximum vibration displacement

336: static displacement

338a, 338b: fluorescence images

339: virtual fluorescent image

340: emission filter

Claims (17)

A micro electrode 100 capable of applying a predetermined voltage, a carbon nanotube 110 having a predetermined size attached to one end of the micro electrode 100, and fluorescent nanoparticles attached to one end of the carbon nanotube 110 ( A fluorescent nanoparticle-coupled nanotube cantilever 10 composed of 120); A light source 300 for supplying predetermined light to the fluorescent nanoparticles 120, an excitation filter 310 for transmitting only excitation light in a wavelength band positioned in the irradiation direction of the light to excite the fluorescent nanoparticles 120, and the fluorescence As a result of nanoparticles 120 absorbing the excitation light, a fluorescence optical device including a dichroic mirror 320 for transmitting only the emitted fluorescence and reflecting the excitation light and a photosensor 330 for detecting the transmitted fluorescence ( 30); Receives the fluorescence information formed through the fluorescence optical device 30 from the photosensor 330 to derive the dynamic displacement or static displacement of the fluorescent nanoparticles 120, the predetermined based on the dynamic displacement or the static displacement Control means 40 for calculating a physical quantity; and And output means (50) for outputting the physical quantity information corresponding to the physical quantity received from the control means (40). The nanomechanical sensor using a fluorescent nanoparticle-coupled nanotube cantilever. The method of claim 1, The carbon nanotube 110 is a nano-mechanical sensor using a fluorescent nanoparticle-coupled nanotube cantilever, characterized in that the length to diameter ratio of 50: 1 ~ 1000: 1. The method of claim 1, The carbon nanotube 110 is a nano-mechanical sensor using a fluorescent nanoparticle-coupled nanotube cantilever, characterized in that the multi-walled carbon nanotube can be observed by an optical microscope. The method of claim 1, The carbon nanotube 110 is a nano-mechanical sensor using a fluorescent nanoparticle-coupled nanotube cantilever, characterized in that the carboxyl group 112 is formed at the end. The method of claim 1, The fluorescent nanoparticles 120 are fluorescent nanoparticles having functionalized chemical groups of any one of strapteavidin, biotin, and amine groups (-Amine group) to enable specific binding to biomolecules ( 300) a nano-mechanical sensor using a fluorescent nanoparticle-coupled nanotube cantilever. The method of claim 1, The fluorescent nanoparticles 120 is any one of quantum dots (Quantum Dots) of several nanometers, fluorescent dyes (Dye) of several nanometers and a single fluorescent nanoparticles of several hundred nanometers in size, characterized in that Nanomechanical sensor using nanotube cantilever. The method of claim 1, The photosensor 330 is a nano-mechanical sensor using a fluorescent nanoparticle-coupled nanotube cantilever, characterized in that the four-segment photosensor. The method of claim 1, The fluorescence optical device 30 further includes a first lens 305 for collimating the light supplied from the light source 300 between the light source 300 and the excitation filter 310. Nanomechanical sensor using nanoparticle-coupled nanotube cantilever. The method of claim 1, The fluorescent optical device 30, A second lens 315 for simultaneously converging the reflected excitation light and the fluorescence between the dichroic mirror 320 and the fluorescent nanoparticles 120; and The nano-mechanical sensor using a fluorescent nanoparticle-coupled nanotube cantilever further comprises a third lens (325) for forming the fluorescence between the dichroic mirror (320) and the photosensor (330). The method of claim 1, The fluorescence optical device 30 further comprises an emission filter 340 for extracting the fluorescence between the dichroic mirror 320 and the photosensor 330, characterized in that the fluorescent nanoparticle-coupled nanotube cantilever. Nano mechanical sensor using The method of claim 1, The nano-mechanical sensor using the fluorescent nanoparticle-coupled nanotube cantilever, characterized in that it further comprises a nano stage (20) mounted to the fluorescent nanoparticle-coupled nanotube cantilever (10). The method of claim 11, The nano-stage 20 is a nano-mechanical sensor using a fluorescent nanoparticle-coupled nanotube cantilever, characterized in that the drive by three-axis control. A step of coupling a predetermined material to the carbon nanotubes 110 to which the fluorescent nanoparticles 120 are attached (S100); Acquiring fluorescence information from a photosensor 330 embedded in the fluorescence optical device 30 in response to the bending displacement of the carbon nanotubes 110 (S110); The control means 40 is connected to the fluorescence optical device 30 to measure the bending displacement of the fluorescent nanoparticles 110 from the fluorescence information to measure the static displacement or dynamic displacement of the fluorescent nanoparticles 120 ( S120); Calculating, by the control means 40, the physical quantity of the combined material through the static displacement or the dynamic displacement of the fluorescent nanoparticle 120 (S130); and And outputting the physical quantity information corresponding to the calculated physical quantity (S140). The method of sensing a nanomechanical sensor using a fluorescent nanoparticle-coupled carbon nanotube, comprising: an output means (50). The method of claim 13, The bound material is a nanomechanical sensor using fluorescent nanoparticle-coupled carbon nanotubes, characterized in that a single biomolecule which is any one of a deoxyribonucleic acid (DNA), a protein, a ligand, and a receptor. Sensing method. 15. The method of claim 14, The derived physical quantity is nanoparticles using fluorescent nanoparticle-coupled carbon nanotubes, characterized in that the fine force of any one of the binding force between the heterogeneous biomolecules, single protein folding force through the static displacement measurement of the carbon nanotubes (110) Sensing method of mechanical sensor. The method of claim 13, The coupled material is a sensing method of a nanomechanical sensor using a fluorescent nanoparticle-coupled carbon nanotubes, characterized in that the gas molecules. The method of claim 16, The derived physical quantity is a sensing method of a nanomechanical sensor using a fluorescent nanoparticle-bonded carbon nanotubes, characterized in that the concentration of the gas molecules in accordance with the change in the natural frequency of the carbon nanotubes (110).

Images