WO2011136548A2

WO2011136548A2 - Spr gas sensing device manufacturing method using molecularly imprinted polymer

Info

Publication number: WO2011136548A2
Application number: PCT/KR2011/003053
Authority: WO
Inventors: Chanryang Park; Hang Choi; Youngsub Kim; Hochul Chung; Sungwoo Jang
Original assignee: Gs Engineering & Construction Corp.
Priority date: 2010-04-30
Filing date: 2011-04-27
Publication date: 2011-11-03
Also published as: KR100977292B1; WO2011136548A3

Abstract

Disclosed is a surface plasmon resonance (SPR) gas sensor chip manufacturing method of depositing a metal layer on a substrate and depositing a thin film sensing layer on the metal layer. The method includes depositing self-assembled monolayers (SAMs) on the metal layer, depositing a radical initiator for depositing a molecularly imprinted polymer (MIP) on the SAMs, and mixing a template monomer, a functional monomer and a cross linker and optically reacting and removing the template monomer through the irradiation of ultraviolet (UV) light based on an absorption wavelength of the radical initiator, thereby forming an imprinted space in the thin film sensing layer.

Description

[DESCRIPTION]

[Invent ion Tit le]

SPR GAS SENSING DEVICE MANUFACTURING METHOD USING MOLECULARLY IMPRINTED POLYMER

[Technical Field]

The present invention relates to a surface plasmon resonance (SPR) gas sensor chip manufacturing method using a molecular ly imprinted polymer. More particularly, the present invention relates to an SPR gas sensor chip manufacturing method using a molecularly imprinted polymer, which can sense several tens of parts per billion (ppb) of gas and ensure the selectivity, stability and reproducibility of gas sensing.

[Background Art]

In general, surface plasmon resonance (SPR) refers to a collective charge density oscillation of electrons, which occurs at a surface of a metal thin film (metal layer).

A surface plasmon wave (SPW) is generated by the oscillation of charge density. Here, the SPW refers to a surface electromagnetic wave advancing along the interface between a metal thin film and a dielectric (thin film sensing layer) that constitutes a surface of a gas sensor chip.

In such a surface plasmon phenomenon, metals such as gold (Au), silver (Ag), copper (Cu) and aluminum (Al), which have negative dielectric constants while containing free electrons, are frequently used. Among these metals, Ag, which has the most acute SPR curve, and Au, which has excellent surface stability, are generally used.

Specifically, when an electric field is applied to the interface between two media having different dielectric constants on the outside, i.e., the interface between a metal thin film and a dielectric, surface charges are induced at the interface between the two media because of the discontinuity of a vertical component in the electric field, and an SPW is generated by the oscillation of the surface charges.

Unlike the electromagnetic wave in the free space, the SPW oscillates in parallel to an incidence surface, and has P-polarization. Therefore, in order to excite the surface plasmon optically, a transverse magnetic (TM)-polar ized electromagnetic wave should be applied.

The TM-polarized incident wave is totally reflected on the interface of the metal thin film, and the intensity of the evanescent wave decreases exponentially from the interface into the metal thin film.

Thus, at a specific incident angle and thickness of the thin film, the phase of the incident wave in the direction parallel to the interface matches that of the SPW propagating along the interface between the metal thin film and the dielectric so that a resonance occurs.

In this instance, the optical energy of the incident wave is absorbed into the metal thin film and reflection waves disappear, which is referred to as the surface plasmon resonance (SPR).

The angle at which the reflectance of incident light is minimum is referred to as an SPR angle.

When the structure or environment of the dielectric that comes in contact with the surface of the metal thin film is changed, the SPR angle at which the reflectance of light becomes minimum is changed due to a change in an effective refractive index.

Thus, using the SPR principle, a change in environment of a substance can be measured optically. Using the SPR principle, selective combination or separation between various substances can be sensed through a change in an SPR angle by chemically or physically modifying the surface of the metal thin film. Accordingly, an SPR sensor can be used as a high-sensitivity chemical sensor (gas sensor).

When a gas sensor chip is manufactured using the SPR, it is very important to employ a method that ensures sensitivity, selectivity and reproducibility of gas which is to be sensed by the gas sensor chip.

Particularly, a means applicable to a method for selectively sensing a desired gas is known in the art as a molecular ly imprinted polymer (MIP).

The MIP refers to a polymer obtained by compounding a polymer using a monomer combined with a certain template as a starting material and then removing the template, so that the MIP has an imprinted space in the same shape as the template.

Only a template with the same shape can be introduced in the imprinted space, and molecules with a different steric structure from the template cannot be introduced in the imprinted space. Hence, a gas corresponding to the template is selectively sensed using a polymer having the imprinted space.

This is the same mechanism as that of Fischer' s lock-and-key concept, in which an antibody formed against an antigen selectively interacts with only the antigen, or the receptor theory, in which an enzyme inside an organism is active only with respect to a specific substrate (a basic preparation method of an MIP has been disclosed in E.U. Patent No. 0190228.)

In order to use the SPR sensor as the high-sensitivity chemical sensor (gas sensor), it is necessary to develop a technique of applying the SPR phenomenon to an MIP, and forming (depositing) a nano-thick sensing layer imprinted with the same shapes of molecules of a gas to be sensed. Particularly, the MIP should be compounded as a polymer with the same shape and size of the molecules of the gas to be sensed so as to apply a non- covalent molecular mechanism to the molecules of the gas to be sensed.

When the MIP is used as a sensing layer, the sensing layer should not be easily changed and should maintain stability against moisture and heat so as to ensure the reproducibility and stability of gas sensing.

However, such a technique has yet to be proposed, and therefore, it is necessary to develop the technique.

[Disclosure]

[Technical Problem]

The present invention is conceived to solve the aforementioned problems. An object of the present invention is to provide a surface plasmon resonance (SPR) gas sensor chip manufacturing method using a molecular ly imprinted polymer, in order to apply an SPR phenomenon to a gas sensor chip.

Another object of the present invention is to provide an SPR gas sensor chip manufacturing method using a molecularly imprinted polymer, which can sufficiently ensure sensitivity, selectivity and reproducibility of a gas to be sensed when applying the SPR phenomenon to the gas sensor chip.

Still another object of the present invention is to provide an SPR gas sensor chip manufacturing method using a molecular ly imprinted polymer, which can improve sensitivity and selectivity of the gas to be sensed by several tens of parts per billion (ppb), and improve reproducibility and stability without change in quality due to ambient environment, moisture and heat.

Additional features of the present invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the present invention. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the present invention as claimed.

[Technical Solution]

In accordance with an aspect of the present invention, there is provided a surface plasmon resonance (SPR) gas sensor chip manufacturing method which is performed by depositing a metal layer on a substrate and depositing a thin film sensing layer on the metal layer, the method including depositing self-assembled monolayers (SAMs) on the metal layer, and depositing a polymer layer that is a molecularly imprinted polymer (MIP) on the SAMs.

The depositing of the polymer layer may include depositing a radical initiator on the SAMs, and performing polymerization of the deposited radical initiator by irradiating ultraviolet (UV) light onto the deposited radical initiator according to an absorption wavelength of the deposited radical init iator .

The radical initiator may include a template monomer, a functional monomer and a cross linker.

An imprinted space may be formed in the thin film sensing layer as the functional monomer combined with the template monomer of the radical initiator is removed by the irradiation of the UV light. [Advantageous Effects]

According to embodiments of the present invention, the thickness of a sensing layer can be controlled to be, for example, several tens to several hundreds of nanometers based on a gas to be sensed, and a functional monomer can be selected and controlled based on a template monomer, so that it is possible to control the shape and size of the gas to be sensed.

Accordingly, it is possible to manufacture a non-covalent molecularly imprinted gas sensor chip through the interaction between a surface of a molecularly imprinted sensing layer and molecules of the gas to be sensed.

Thus, it is possible to sufficiently ensure the selectivity and sensitivity of a gas to be sensed. Further, since the sensing layer is a polymer layer, the stability against the ambient environment, moisture and heat is excellent, and the quality is not easily changed, thereby improving the reproducibility and stability.

[Description of Drawings]

FIG. 1 is a configuration view of a surface plasmon resonance (SPR) sensing system using a gas sensor chip.

FIG. 2 is a vertical sectional view illustrating an embodiment of the gas sensor chip using the SPR, applicable to the present invention.

FIGS. 3 and 4 are conceptual views illustrating a state in which a self-assembled monolayer (SAM) is formed on a metal layer.

FIG. 5 is a configuration view of a radical initiator according to an embodiment of the present invention.

FIG. 6 is a view illustrating a process in which a starting material for forming a polymer layer is deposited on the metal layer by the SAM and glutaraldehyde.

FIG. 7 is a view illustrating a state in which ultraviolet (UV) light is irradiated onto the deposited radical initiator so as to form a molecular- level imprinted space.

FIG. 8 is a view illustrating a state in which a template is imprinted on a thin polymer layer formed on a thin film sensing layer by the UV light.

[Description of Reference Numerals] 110 : molecular ly imprinted gas sensor chip

111 : glass substrate

113 : metal layer

114: thin film sensing layer

115: prism

200: gas

iMode for Invention]

The present invention is described in more detail hereinafter with reference to the accompanying drawings, in which embodiments of the present invention are shown. This present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure is thorough, and will fully convey the scope of the present invention to those skilled in the art.

FIG. 1 is a configuration view of an SPR sensing system using a gas sensor chip.

Referring to FIG. 1, a general SPR sensing system is used to sense and analyze interactions between various chemical substances using the SPR, and may largely include a gas sensor chip, an optical unit, a reaction chamber, a gas supply unit, a signal processing unit, and the like. However, the present invention is not necessarily limited thereto.

The optical unit includes a light emitting unit 120, a light receiving unit 130, a rotating stage 140, and the like. The rotating stage 140 is, for example, provided with a stepping motor, and the stepping motor is driven by a stepping motor driver 160.

The gas supply unit may include supply gases 211, 212 and 213, throttle valves 221, 222 and 223, mass flow controllers (MFCs) 231 and 232, a digital flow controller 240, a mixer 250, and the like.

The signal processing unit (not shown) converts the measured reflectance of incident light into an electrical signal and is then connected to a lab view 170 or a personal computer (PC).

The optical unit may also be divided into a light source, a polarization converter and an optic detector, which are required to excite the SPR.

In this case, the light source, i.e., the light emitting unit 120, may be composed of, for example, a laser diode 121, a light emitting diode or the like. The light receiving unit 130 may be composed of, for example, a charge-coupled device (CCD) camera, a photodiode, a phototransistor or the like.

Also, the polarization converter includes a filter 122 and a beam expander 123. The polarization converter filters a light source provided from the light emitting unit 120 and then P-polarizes the filtered light source.

A glass substrate (generally, referred to as an SPR sensor chip) having a metal layer deposited thereon is mounted in the reaction chamber 150. The reaction chamber includes a gas inlet, a sample reactor, a gas outlet, and the like. The reaction chamber is disposed to come in contact with a thin film sensing layer of the gas sensor chip 110.

Also, the signal processing unit (not shown) may include an electronic circuit and driving software, which can measure the reflectance of incident 1 ight in real time.

Meanwhile, the SPR sensing system may use various sensing methods such as an angle-changing method in which the SPR is sensed while changing the incident angle of incident light, and a wavelength-variable method in which the SPR is sensed while changing a wavelength of incident light at a constant incident angle. It is apparent to those skilled in the art that the sensing method may be changed depending on the purpose of use or the object to be sensed.

For example, the system can identify whether or not a specific gas is sensed by the gas sensor chip according to the present invention. When the system is installed in a specific space by removing the digital flow controller 240, the supply gases 211, 212 and 213, the throttle valves 221, 222 and 223, the MFCs 231 and 232, the digital flow controller 240 and the mixer 250, and by changing or modifying the shapes of the rotating stage 140 and the reaction chamber 150, the system can be easily installed and operated. An overall size of the sensing system may be controlled when the stepping motor driver 160 and the lab view 170 are, for example, replaced by a microprocessor and a separate driver and a display unit.

< Molecular ly imprinted gas sensor chip 110 of the present invent ion> Regarding a molecularly imprinted gas sensor chip 110 used in the present invention, FIG. 2 is a vertical sectional view illustrating an embodiment of the molecularly imprinted gas sensor chip using the SPR, applicable to the present invention. Hereinafter, a method of sensing a specific gas through the gas sensor chip will be described.

Referring to FIG. 2, the molecularly imprinted gas sensor chip 110 using the SPR may include a glass substrate 111 on which a metal layer 113 is deposited, the metal layer 113 that reacts with incident light to generate the SPR, a thin film sensing layer 114 joined with the metal layer 113 to sense a gas that comes in contact therewith by moving the wavelength of a surface wave generated by the SPR, a prism 115 that reflects the light incident on the light emitting unit so as to allow a converted SPW to be incident on the light receiving unit, an immersion oil layer 116, and the like.

The molecularly imprinted gas sensor chip 110 has a structure obtained by depositing, for example, gold (Au) on the glass substrate 111 to form the metal layer 113, forming the thin film sensing layer 114 that is a dielectric on the metal layer and then joining the glass substrate 111 with the prism 115.

In the molecularly imprinted gas sensor chip 110, light is incident on the prism 115 by the light emitting unit 120, and the light receiving unit 130 analyzes the light reflected from the prism 115, thereby sensing a gas 200 reacting with the thin film sensing layer 114.

In this instance, a numerical aperture (NA) is necessarily great so as to increase resolution. The immersion oil layer 116 may also be formed to increase the NA.

That is, when light emitted from a light source is absorbed as an SPW determined by refractive indices of the metal layer 113 and the thin film sensing layer 114, an SPR phenomenon occurs. Then, when the thin film sensing layer 114 chemically or physically reacts with a specific component of gas, the specific component of the gas can be quantitatively sensed by analyzing the change in the SPW formed between the metal layer 113 and the thin film sensing layer 114.

Hereinafter, a process of forming the thin film sensing layer 114 of the gas sensor chip, which is formed of an MIP, will be described.

In the method of this embodiment, an imprinted space having the same shape as a template is formed in the thin film sensing layer 114 by forming a polymer in a metal layer using a functional monomer combined with a template monomer (template) such as toluene as a radical initiator and then removing the functional monomer.

- First process: a process of depositing the metal layer 113 on the substrate 111

Referring to FIG. 2, the molecularly imprinted gas sensor chip according to the present invention may include, for example, a substrate 111, a metal layer 113, a thin film sensing layer 114 and a prism 115.

In this case, the prism 115 and the substrate 111 are formed of BK7 having the same characteristic (glass with a refractive index of 1.515509 (λ =637 nm)), and are joined with each other, serving as an optical member that reflects incident light.

The substrate 111 may be formed to have a thickness of approximately

0.8 mm.

Subsequently, the metal layer 113 is deposited on the substrate 111. Here, the metal layer 113 may be formed in a single-layered structure using Au or silver (Ag). This is because Au is most advantageous in forming a thin metal layer, and also because it is a stable material which is not oxidized at a temperature lower than its melting point, and hardly reacts with oxygen in the air.

The thin film sensing layer 114 of the present invention is formed on the metal layer 113 formed by depositing the Au on the substrate 111.

Meanwhile, when the Au is deposited on the substrate 111, the thickness of the Au is controlled to be 10 to 50 nm. This is because the entire thickness of the metal layer deposited on the substrate is a very important factor in applying the gas sensor chip using the SPR and the optimal SPR phenomenon occurs when the thickness of the metal layer is as mentioned above .

Subsequently, the thin film sensing layer 114 is formed on the substrate 111 having the Au, i.e., the metal layer 113, deposited thereon. Here, the gas to be sensed is imprinted in the thin film sensing layer 114 at a molecular level using the MIP.

The imprinting process will be described in detail as follows.

- Second operation: a process of depositing self-assembled monolayers (SAMs) on the metal layer 113 formed on the substrate 111

SAMs are deposited on the metal layer 113 because the SAMs are a kind of medium for selectively depositing a radical initiator, which will be described later, on the metal layer 113.

In other words, a desired radical initiator is stably deposited on the metal layer by controlling a functional group of the SAMs.

Thus, a specific SAM is deposited on a surface of the metal layer based on the radical initiator.

The SAM will be described in a more detailed manner. Various studies are being conducted on controlling properties of a surface of a solid using an organic substance, and one of these studies regards a technique of forming SAMs. That is, the properties of the surface of the solid are controlled by aligning SAMs on the surface of the solid.

The SAMs are organic monolayers that are spontaneously formed and regularly aligned on a surface of a solid (metal layer 113). The molecular structure of the SAM is generally composed of a head group, an alkyl chain (hydrocarbon chain) and a terminal group (functional group), as shown in FIGS. 3 and 4, which illustrate a state in which the SAMs are deposited on the metal layer 113 made of the Au.

The head group is a part that is chemically absorbed on the metal layer 113, and functions to form a closed packed monolayer.

The alkyl chain (hydrocarbon chain) functions to regularly align the monolayer formed by the head group through the Van der Waals interaction between long alkyl chains.

The terminal group serves as a functional group, and may include various functional groups (e.g., NH₂,0H and C00H)so that the SAM has a certain function.

A method of immersing a substrate in SAMs in a solution state at a normal temperature may be used as the method of depositing the SAMs on the surface of the solid (metal layer).

For example, the SAMs may be deposited on the metal layer formed on the substrate 111 by immersing the substrate 111 on which Au is formed as the metal layer in an SAM solution (e.g., a solution diluted up to 1 to 10 mM) and then leaving the substrate 111 for 48 hours.

FIG. 4 illustrates an embodiment of the state in which a plurality of SAMs are formed on the metal layer (Au) 113.

The factors that influence the depositing of the SAM are depositing temperature, kind and concentration of the solution, purity of the SAM, concentration of oxygen in the solution, cleanness of the substrate, and the like.

Since the SAM of the metal layer formed on the substrate is deposited to a thickness of several tens of by controlling these factors, the influence on the entire thickness of the thin film sensing layer (dielectric) is very small, and the SAM easily reacts to a radical initiator.

- Third process: a process of preparing and depositing a radical initiator as a starting material

In the present invention, the imprinted space in the same shape as that of the template monomer is formed in the thin film sensing layer 114 by forming a polymer using the functional monolayer combined with the template monomer such as toluene as a radical initiator and then removing the template monomer. In this instance, the shape and size of molecules of the gas (toluene or the like, which is the template monomer) to be sensed can be controlled according to the selection of a specific functional monomer, and it is possible to compound a non-covalent molecularly imprinted polymer through the interaction between a surface of the molecularly imprinted dielectric and the molecules of the gas to be sensed.

Put simply, a thin polymer layer (polymer) is deposited on the metal layer 113 using the SAMs described above, and an imprinted space corresponding to a specific gas is formed in the polymer layer at the molecular level.

Thus, the radical initiator is first prepared as a starting material so as to form the polymer layer having the imprinted space formed therein.

As shown in FIG. 5, the radical initiator is prepared first by largely mixing a template monomer, a functional monomer and a cross linker.

The template monomer refers to a gas to be sensed, i.e., a gas that serves as a sensing target. For example, the gas (template monomer) may be at least one of benzene, toluene, ethylbenzene, xylene, and formaldehyde

The functional monomer has a functional group capable of being combined with a portion of the template monomer. The functional monomer determines a non-covalent molecularly imprinted polymer through the shape and size of the imprinted molecules and the interaction between the molecules of the gas to be sensed.

The cross linker may be a cross-linking agent for maintaining the arrangement of the functional monomer combined with the template monomer.

Thus, it can be seen that the radical initiator is first prepared as a starting material for forming a polymer layer (polymer) by mixing a template monomer, a functional monomer and a cross linker.

As will be described later, the starting material is produced in the imprinting process by irradiating ultraviolet (UV) light to initiate a polymerization reaction. For this reason, the starting material is referred to as a radical initiator.

Meanwhile, in order to form the polymer layer, each of the monomers may be selected and prepared using various techniques known in the art. Therefore, their descriptions will be omitted.

When the starting material for forming the polymer layer is first prepared as shown in FIG. 6, the starting material is deposited on the metal layer 113 using the SAMs.

To this end, the starting material is dissolved in a solvent (DMF) by controlling the concentration of the starting material, and glutar aldehyde is combined with the SAMs. Then, the starting material is combined with a functional group of the glutar aldehyde.

Thus, it can be seen that the starting material is deposited on the metal layer 111 as the radical initiator for forming the polymer layer using the SAMs and the glutar aldehyde, as shown in FIG. 6.

- Fourth process: a process of determining the nano-thickness of the MIP by irradiating UV light

As shown in FIG. 7, UV light is irradiated onto the radical initiator deposited on the thin film sensing layer 114 so as to form the imprinted space at the molecular level using the MIP.

In this instance, the UV light is irradiated based on the radical initiator in consideration of a wavelength range of the UV light, irradiation time, power and the like. Polymerization is initiated by breaking chemical bonds of the radical initiator. In this case, the nano-thickness of the thin film sensing layer 114 is controlled.

The nano-thickness of the thin film sensing layer 114 is controlled by a wavelength of the UV light based on the absorption wavelength of the radical initiator, irradiation intensity and irradiation time.

Particularly, the wavelength of the UV light is determined based on the chemical structure of the radical initiator, and hence there are various conditions. The molecularly imprinted gas sensor chip in which the SPR phenomenon occurs can be manufactured to have an optimal thickness by controlling the irradiation time and power. The irradiation time and intensity of the UV light may be determined according to a mixture ratio of the radical initiator, the template monomer, the functional monomer and the cross linker.

Finally, As shown in FIG. 8, the functional monomer combined with the template monomer in the radical initiator is removed, the template monomer is imprinted in the polymer layer with the optimal nano-thickness formed in the thin film sensing layer through the space occupied by the removed functional monomer .

Accordingly, the formation of the molecularly imprinted thin film sensing layer 114 according to the present invention is completed.

The gas sensing method of the gas sensor chip with the molecularly imprinted thin film sensing layer using the MIP according to the present invention is a method of sensing a gas by reflecting light incident from the light emitting unit and sensing an SPW changed in the light receiving unit. First, the molecularly imprinted gas sensor chip with the thin film sensing layer 114 is prepared using the MIP (S210).

Subsequently, the intensity of light to be incident is controlled (S220). As the intensity of the incident light is increased, the sensitivity may be increased.

Subsequently, the light whose intensity is controlled is incident on the prism in the molecularly imprinted gas sensor chip (S230).

Subsequently, the SPW determined by the refractive index of the thin film sensing layer 114 in the molecularly imprinted gas sensor chip is generated using the SPR (S240).

Subsequently, the thin film sensing layer physically or chemically reacts with gas containing a specific component (S250). When the thin film sensing layer using the MIP is interacted with the specific gas, a change in the intensity of reflected light is detected as an electrical signal, corresponding to the change in the refractive index of the thin film sensing layer (S260).

Subsequently, the sensed component of the gas is quantitatively analyzed, corresponding to the detected electrical signal (S270).

Although the present invention has been explained by the embodiments shown in the drawings described above, it should be understood to the ordinary skilled person in the art that the present invention is not limited to the embodiments but rather that various changes or modifications thereof are possible without departing from the spirit of the present invention. Accordingly, the scope of the present invention shall be determined only by the appended claims and their equivalents.

Claims

[CLAIMS]

[Claim 1]

A surface plasmon resonance (SPR) gas sensor chip manufacturing method which is performed by depositing a metal layer on a substrate and depositing a thin film sensing layer on the metal layer, the method comprising:

depositing self-assembled monolayers (SAMs) on the metal layer; and depositing a polymer layer that is a molecularly imprinted polymer (MIP) on the SAMs.

[Claim 2]

The method of claim 1, wherein the depositing of the polymer layer compr i ses :

depositing a radical initiator on the SAMs; and

performing polymerization by irradiating ultraviolet (UV) light onto the deposited radical initiator.

[Claim 3]

The method of claim 2, wherein the deposited radical initiator that is a starting material is formed of a polymer layer obtained by mixing a template monomer, a functional monomer and a cross linker.

[Claim 4]

The method of claim 3, wherein an imprinted space is formed in the thin film sensing layer by chemically reacting and removing the- functional monomer combined with the template monomer of the radical initiator through the irradiation of the UV light.

[Claim 5]

The method of claim 3, wherein the template monomer is at least one of benzene, toluene, ethylbenzene, xylene andformaldehyde.

[Claim 6]

The method of claim 5, wherein the template monomer is formed to have a nano-thickness at which an SPR phenomenon occurs.

[Claim 7]

The method of claim 6, wherein the nano-thickness of the template monomer is controlled by a wavelength of the UV light based on an absorption wavelength of the radical initiator, irradiation strength, irradiation time and a mixture ratio of the template monomer, the functional monomer and the cross linker.

[Claim 8]

The method of claim 3, wherein the SAM that is an organic monolayer includes a head group chemically adsorbed on a surface of a solid; an alkyl chain for regularly aligning the monolayer formed by the head group; and a terminal group that is a functional group.

[Claim 9]

The method of claim 7, wherein glutar aldehyde is combined with the SAM, and the starting material is then combined with a functional group of the glutar aldehyde.

[Claim 10]

The method of claim 7, wherein the depositing of the SAMs on the metal layer is performed by immersing the substrate having the metal layer deposited thereon in an SAM solution.

[Claim 11]

The method of claim 1, wherein the gas sensor chip further comprises a prism on which light is incident from a light emitting unit so as to reflect a surface plasmon wave to a light receiving unit in the substrate.

[Claim 12]

The method of claim 11, wherein an immersion oil layer is further provided between the substrate and the prism.

[Claim 13]

The method of claim 12, wherein the metal layer is a layer formed of gold (Au).

[Claim 14]

The method of claim 13, wherein the metal layer has a thickness of 10 to 50 nm.