TECHNICAL FIELD
[0001] The present invention relates to a cucurbituril derivative-bonded solid substrate,
and more particularly, to a solid substrate covalently bonded with a cucurbituril
derivative which can immobilize a biomaterial by a non-covalent interaction, and its
applications.
BACKGROUND ART
[0002] After the human genome sequence was drafted in 2000, gene expression could be understood
at mRNA level. Thereafter, developments of personalized medicines or diagnostic reagents
based on Individual genome information have been anticipated. Therefore, there has
arisen a need to rapidly trace the expression levels of a large number of genes. In
this regard, there was developed a DNA chip capable of simultaneously performing assays
of a thousand to ten thousand genes. However, a gene assay alone cannot provide information
about proteins which are not only gene products but also biomaterials essential for
biological activity. Therefore, there has been suggested a protein chip, a corresponding
concept of a DNA chip, which can perform simultaneous assays of a large number of
proteins.
[0003] Reference will now be made to FIGS. 1 and 2 of the accompanying diagrammatic drawings,
in which FIG. 1 illustrates a protein chip; FIG. 2 illustrates degeneration of a protein;
and FIG. 3 illustrates a cucurbituril derivative-covaient bonded solid substrate .
[0004] The concept of the protein chip is based on the protein microarrays which contain
chemically or biochemically treated surfaces for specific interaction with proteins
of interest. As illustrated in FIG. 1, in which 1 is a functional group for linkage
with a solid substrate, 2 is a molecular body, 3 is a functional group for linkage
with a biomaterial, and 4 is the solid substrate, a protein chip can be made as follows.
First, a thin film is formed on a solid substrate 4 using compounds with functional
groups 1 for linkages with the solid substrate 4 and another functional groups 3 for
linkages with biomaterials such as proteins. Then, biomaterials such as proteins can
be immobilized on the solid substrate 4 via chemical or physical interactions between
biomaterial and the terminal functional group 3. FIG. 1 illustrates the solid substrate
4 having a thin film made of compounds with the functional groups 1 for linkages with
the solid substrate 4 and the functional groups 3 for linkages with biomaterials such
as proteins.
[0005] Hitherto, many researchers have used covalent bonds between the functional groups
3 of FIG. 1 and proteins to Immobilize the proteins on a solid substrate. When covalent
bonds between the functional groups 3 of FIG. 1 and proteins are formed, the proteins
can be immobilized on the surface of a solid substrate.
[0006] However, it is well-known that their specificities or activities toward substrates
are seriously affected by the immobilization method, because the specificity and activity
are strongly related to their specific three-dimensional structures and orientation
of their active sites, referring to the following FIG. 2, in which 1 is a solid substrate,
5 is a linkage layer, 6 is a protein with a damaged active site, and 7 is a protein
with a preserved active site. Therefore, the three-dimensional structures of proteins
may be damaged when the proteins are covalently bonded to a solid substrate, thereby
causing degeneration of the proteins, like a protein 6 of FIG. 2. This is because
the function of proteins is dependent on their specific three-dimensional structures
formed by chains of amino acids constituting the proteins. To maintain the function
of a protein chip, like a protein 7 of FIG. 2, an active site must not be bonded to
the linkage layer 5 to preserve the functionality of the active site.
[0007] To solve this problem, many methods have been developed for immobilizing proteins
to a surface of a solid substrate via non-covalent bonds.
[0008] By way of an example, a study about the attachment of proteins to a solid substrate
by a coordination bond was reported. Paborsky et al. suggested a coordination linkage
between proteins fused with histidine, which is an amino acid known to well bind with
Ni, Cu, etc., and a surface of a solid substrate to which Ni is attached by nitrilotriacetic
acid (NTA) [
Paborsky, L. R.; Dunn, K. E.; Gibbs, C. S.; and Dougherty, J. P., Anal. Biochem. 1996,
234, pp. 60-65].
[0009] Frey et al. reported the attachment of an intermediate, such as polylysine, capable
of ionically binding with proteins, to a solid substrate, to immobilize the proteins
on the solid substrate [
Frey, Brian L.; Jordan, Claire E.; Kornguth, Steven; and Corn, Robert M., Anal. Chem.
1995, 67, 4452-4457].
[0010] Recently, Tae-Sun Kim et al. reported a hydrogen bond between proteins and a solid
substrate having crown ether derivatives, paying attention to a hydrogen bond between
ammonium groups abundantly present at non-active sites of proteins and crown ether
groups (Korean Patent Application Nos.
10-1999-0061074 and
10-2000-0038491).
[0011] However, the bond strength of most non-covalent bonds is much less than that of covalent
bonds. Therefore, proteins having non-covalent bonds with a solid substrate may be
detached from the solid substrate when contact with chemical materials used in immunoassay.
In this regard, many attempts have been made to immobilize proteins on a solid substrate
via stronger non-covalent bonds.
[0012] Recently, Yao and co-workers reported a solid substrate for a protein chip in which
avidin, a type of protein, is immobilized on the solid substrate via a covalent bond
[
Lesaicherre, M.-L.; Lue, R. Y. P.; Chen, G. Y. J.; Zhu, Q.; and Yao, S. Q. J., Am.
Chem. Soc. 2002,124, 8768]. Avidin is known to bind with four small molecules of biotin by a coupling constant
of about 10
15 M
-1, which is the strongest non-covalent bond among currently known non-covalent bonds
[
Wilchek, M.; Bayer, E. A. Avidin-Biotin Technology. In Methods in Enzymology 1990,184]. According to the report by Yao et al., probe proteins are fused with biotin and
then are immobilized on a solid substrate treated with avidin. Reportedly, the probe
proteins are not detached from the solid substrate even under a very severe environment.
However, this method has an economical limitation of avidin being costly, even though
there is an advantage in that a coupling constant of avidin-biotin interaction is
very large.
[0013] Therefore, a cost effective method for immobilizing proteins to a solid substrate
using a non-covalent bond with strong interaction is required.
[0014] WO 2004/072151 (Article 54(3) EPC document) discloses a cucurbituril-bonded silica gel useful for
removal of air pollutants or water contaminants, and separation and purification of
biological, organic, inorganic, or ionic substances.
[0015] WO 2003/004500 discloses cucurbituril derivatives of specific formulations, having enhanced solubility
in common solvents.
DETAILED DESCRIPTION OF THE INVENTION
Technical Goal of the Invention
[0016] The present invention provides a cucurbituril derivative-bonded solid substrate in
which a cucurbituril derivative is covalently bonded to a modified solid substrate.
[0017] The present invention also provides a protein chip using the cucurbituril derivative-bonded
solid substrate.
[0018] The present invention also provides a gene chip using the cucurbituril derivative-bonded
solid substrate.
[0019] The present invention also provides a sensor for biomaterial assay using the cucurbituril
derivative-bonded solid substrate.
Disclosure of the Invention
[0020] According to an aspect of the present invention, there is provided a cucurbituril
derivative-bonded solid substrate wherein the substrate is a glass, a silicon wafer,
an indium tin oxide (ITO) glass, an aluminum oxide substrate, or a titanium dioxide
substrate and is selected from the group consisting of substrates represented by Formulae
3 through 6:

wherein each n is independently an integer of 1 to 20;

wherein n is an integer of 1 to 20 and X is a dialkylsulfide group with a substituted
or unsubstituted alkyl moiety of C
1-C
20 or a substituted or unsubstituted alkyl group of C
1-C
20;

wherein n is an integer of 1 to 20; and

wherein n is an integer of 1 to 20.
[0021] According to another aspect of the present invention, a cucurbituril derivative-bonded
solid substrate is selected from the group consisting of substrates represented by
Formulae 8 through 11:

wherein each n is independently an integer of 1 to 20;

wherein each n is independently an integer of 1 to 20 and X is a dialkylsulfide group
with a substituted or unsubstituted alkyl moiety of C
1-C
20 or a substituted or unsubstituted alkyl group of C
1-C
20;

wherein each n is independently an integer of 1 to 20 and X is a dialkylsulfide group
with a substituted or unsubstituted alkyl moiety of C
1-C
20 or a substituted or unsubstituted alkyl group of C
1-C
20; and

wherein each n Is Independently an integer of 1 to 20.
[0022] The solid substrate may be a substrate made of gold, silver, platinum, or copper.
[0023] The invention extends to a protein chip, a gene chip and a sensor for biomaterial
assay, all including a cucurbituril derivative-bonded solid substrate according to
any of the preceding aspects of the invention.
[0024] Hereinafter, examples of the present invention will be described.
[0025] A cucurbituril derivative represented by Formula 1 below has a functional group suitable
for a covalent linkage with a solid substrate:

wherein n is an integer of 4 to 20, and R
1 and R
1' are each independently an alkenyloxy group with an unsaturated bond end and a substituted
or unsubstituted alkyl moiety of C
1-C
20, a carboxyalkylsulfinyloxy group with a substituted or unsubstituted alkyl moiety
of C
1-C
20, a carboxyalkyloxy group with a substituted or unsubstituted alkyl moiety of C
2-C
8, an aminoalkyloxy group with a substituted or unsubstltuted alkyl moiety of C
2-C
8, or a hydroxyalkyloxy group with a substituted or unsubstituted alkyl moiety of C
2-C
8.
[0026] The solid substrate may be a glass, a silicon wafer, an indium tin oxide (ITO) glass,
an aluminum oxide substrate, or a titanium dioxide substrate. Examples of hydroxycucurbituril
and its mother cucurbituril used as a synthetic material for the compound of Formula
1 above are disclosed together with their structural formulae and synthetic methods
in Korean Patent Application Nos.
02-68362,
02-318,
01-57573,
01-39756, and
00-33028.
[0027] The cucurbituril derivative of Formula 1 is covalently bonded to a codified solid
substrate with various end functional groups to form a desired solid substrate. For
this, a modified solid substrate of Formula 2 below may be used:

wherein R
2 is an alkyl group of C
1-C
10 with an end functional group selected from thiol, amine, epoxy, isocyan, and isothiocyan.
[0028] For example, the modifled substrate of Formula 2 may be prepared by reacting a silane
having an end functional group, such as thiol, amino, and epoxy, with a metal oxide
substrate containing a -OH surface group by washing.
[0029] A cucurbituril-bonded solid substrate can be prepared by covalently bonding the cucurbituril
derivative of Formula 1 with the modified solid substrate of Formula 2. That is, the
cucurbituril derivative of Formula 1 is covalently bonded to the modified solid substrate
of Formula 2 by reacting end functional groups of the cucurbituril derivative, such
as a carboxyl group, an amine group, a hydroxyl group, or an allyl group, with end
functional groups of the modified solid substrate, such as an amine group, an epoxy
group, or a thiol group.
[0030] Examples of the solid substrate thus prepared are presented in the following Formulae
3 through 6 and their preparation methods will now be described.

wherein each n is independently an integer of 1 to 20.
[0031] A substrate of Formula 3 may be obtained by sulfido-bond formation between a cucurbituril
derivative and a solid substrate, in detail, by radical reaction between a thiol-modified
metal oxide substrate and alkenyloxycucurbituril.
[0032] In more detail, the preparation of the substrate of formula 3 by radical reaction
includes, but is not limited to, the steps of:
- (a) dissolving alkenyloxycucurbituril in an organic solvent such as chloroform and
methanol;
- (b) adding a catalytic amount of AIBN (2,2-azobisisobutyronitrile) to the reaction
mixture and then placing the resultant reaction mixture in a crystal tube;
- (c) adding a thiol-modified metal oxide substrate to the reaction mixture;
- (d) removing residual oxygen by the supply of nitrogen or argon to the reaction mixture;
- (e) exposing the reaction mixture to ultraviolet light for several days, for example,
3 days; and
- (f) washing the resultant solution with excess organic solvent followed by filtration
to obtain a metal oxide substrate linked with cucurbituril by a sulfido-bond.
[0033] The exposure to ultraviolet light in step (e) may be substituted by heating at 80
to 120°C.

wherein n is an integer of 1 to 20 and X is a dialkylsulfide group with a substituted
or unsubstituted alkyl moiety of C
1-C
20 or a substituted or unsubstituted alkyl group of C
1-C
20.
[0034] The substrate of Formula 4 may be obtained by amide bond formation between a cucurbituril
derivative and a solid substrate, in detail, by amide bond formation between a carboxyl-ended
cucurbiturile derivative and an amino-modified metal oxide substrate.
[0035] In more detail, the preparation of the substrate of Formula 4 includes, but is not
limited to, the steps of:
- (a) adding 1-ethyl-3-(3-dimethylaminopropyl)carboimidehydrochloride and N-hydroxysuccinimide
or N,N-dimethylacetamide to a solution of carboxyl-ended cucurbituril derivative in
distilled dimethylformamide;
- (b) adding an amino-modified solid substrate to the reaction mixture followed by stirring
at room temperature for 12 hours or more;
- (c) washing the resultant metal oxide substrate with water and an organic solvent
followed by drying to prepare a metal oxide substrate linked with cucurbituril by
an amide bond.

wherein n is an integer of 1 to 20.
[0036] the substrate of Formula 5 may be obtained by ether bond formation between a cucurbituril
derivative and a solid substrate, in detail, by a nucleophilic substitution reaction
between a hydroxyl-ended cucurbituril derivative and an epoxy-modified metal oxide
substrate.
[0037] The preparation of the substrate of Formula 5 by nucleophilic substitution reaction
includes the steps of:
- (a) adding hydroxyalkyloxycucurbituril with an end hydroxyl group to a dimethylformamide
solvent;
- (b) gradually adding an epoxy-modified metal oxide substrate and a catalytic amount
of boron trichloride to the reaction mixture;
- (c) stirring the reaction mixture at room temperature for 1 to 24 hours followed by
further stirring at 85°C for 1 to 24 hours; and
- (d) washing the resultant metal oxide substrate with water and an organic solvent
followed by drying to prepare a metal oxide substrate linked with cucurbituril by
an ether bond.

wherein n is an integer of 1 to 20.
[0038] The substrate of Formula 6 may be obtained by amino bond formation between a cucurbituril
derivative and a solid substrate, in detail by a nucleophilic substitution reaction
between an amino-ended cucurbituril derivative and an epoxy-modified metal oxide substrate.
[0039] The preparation of the substrate of Formula 6 by the nucleophilic substitution reaction
includes the steps of:
- (a) dissolving aminoalkyloxycucurbituril with an end amino group in a phosphate buffer
(pH 7 to 10);
- (b) adding an epoxy-modified metal oxide substrate to the reaction mixture;
- (c) stirring the reaction mixture at room temperature for 1 to 24 hours; and
- (d) washing the resultant metal oxide substrate with water and an organic
solvent followed by drying to prepare a metal oxide substrate linked with cucurbituril
by an amino bond.
[0040] A cucurbituril derivative-bonded solid substrate may also be prepared by covalently
bonding the cucurbituril derivative of Formula 1 to a solid substrate of Formula 7
below:

wherein R
3 is an alkyl group of C
1-C
10 with an end functional group selected from thiol, amine, epoxy, isocyan, and isothiocyan.
[0041] For example, the modified substrate of Formula 7 may be prepared by reacting a thiol
compound having an end functional group, such as thiol, amino, and carboxyl group,
with a metal oxide substrate containing a -OH surface group by washing.
[0042] A covalent bond between the cucurbiturile derivative of Formula 1 and the modifies
solid substrate of Formula 7 enables the formation of another cucurbituril derivative-bonded
solid substrate. That is, the cucurbituril derivative of Formula 1 is covalently bonded
to the modified solid substrate of Formula 7 by reacting end functional groups of
the cucurbituril derivative, such as carboxyl group, an amino group, or a thiol group,
with end functional groups of the modifled solid substrate, such as an amino group,
a carboxyl group, or a thiol group.
[0043] Examples of the solid substrate thus prepared are presented in the following Formulae
8 through 11 and their preparation methods will now be described.

wherein each n is independently an integer of 1 to 20.
[0044] A substrate of Formula 8 may be obtained by sulfide-bond formation between a cucurbituril
derivative and a metal substrate, in detail, by radical reaction between a thiol-modified
metal substrate and alkenyloxycucurbituril.
[0045] In more detail, the preparation of the substrate of Formula 8 by radical reaction
includes, but is not limited to, the steps of:
- (a) dissolving alkenyloxycucurbituril in an organic solvent such as chloroform and
methanol;
- (b) adding a catalytic amount of AIBN (2,2-azobisisobutyronitrile) to the reaction
mixture and then placing the resultant reaction mixture in a crystal tube;
- (c) adding a thiol-modified metal substrate to the reaction mixture;
- (d) removing residual oxygen by the supply of nitrogen or argon to the reaction mixture;
- (e) exposing the reaction mixture to ultraviolet light for several days, for example,
3 days; and
- (f) washing the resultant solution with an excess organic solvent followed by filtration
to obtain a metal oxide substrate linked with cucurbituril by a sulfide-bond.

wherein each n is independently an integer of 1 to 20 and X is a dialkylsulfide group
with a substituted or unsubstituted alkyl moiety of C1-C20 or a substituted or unsubstituted alkyl group of C1-C20.
[0046] The substrate of Formula 9 may be obtained by amide bond formation between a cucurbituril
derivative and a metal substrate, in detail, by amide bond formation between a carboxyl-ended
cucurbituril derivative and an amino-modified metal substrate.
[0047] In more detail, the preparation of the substrate of Formula 9 includes, but is not
limited to, the steps of:
- (a) adding 1-ethyl-3-(3-dimethylaminopropyl)carboimidehydrochloride and N-hydroxysuccinimide
or N,N-dimethylacetamide to a solution of carboxyl-ended cucurbituril in distilled
dimethylformamide;
- (b) adding an amino-modified metal substrate to the reaction mixture followed by stirring
at room temperature for 12 hours or more; and
- (c) washing the resultant metal substrate with water and an organic solvent followed
by drying to prepare a metal substrate linked with cucurbituril by an amide bond.

wherein each n is independently an integer of 1 to 20 and X is a alkylsulfidoalkyl
group with a substituted or unsubstituted alkyl moiety of C1-C20 or a substituted or unsubstituted alkyl group of C1-C20,
[0048] The substrate of Formula 10 may be prepared by amide bond formation between a cucurbituril
derivative and a metal oxide substrate, in detail, by amide bond formation between
a carboxyl-ended cucurbituril derivative and an amino-modified metal oxide substrate.
[0049] In more detail, the preparation of the substrate of Formula 10 includes, but is not
limited to, the steps of:
- (a) dissolving 1-ethyl-3-(3-dimethylaminopropyl)carboimidehydrochloride and N-hydroxysuccinimide
or N,N-dimethylacetamide in distilled dimethylformamide and adding a carboxyl-modified
metal substrate to the reaction mixture;
- (b) adding an amino-ended cucurbituril derivative to the reaction mixture followed
by stirring at room temperature for 12 hours or more; and
- (c) washing the resultant metal substrate with water and an organic solvent followed
by drying to prepare a metal substrate linked with cucurbituril by an amide bond.

wherein each n is independently an integer of 1 to 20.
[0050] The preparation of the substrate of Formula 11 includes the steps of:
- (a) dissolving methylmorpholine and ethylchloroformate to distilled dimethylformamide
and adding a carboxyl-modified metal substrate followed by stirring for several minutes;
- (b) washing the resultant metal substrate with an organic solvent followed by drying
to obtain a metal substrate containing carboxylic anhydride;
- (c) dissolving hydroxyl-ended cucurbituril and methylmorpholine to distilled dimethylformamide
and adding the resultant metal substrate to the reaction mixture; and
- (d) washing the resultant metal substrate with water and an organic solvent followed
by drying to prepare a metal substrate linked with cucurbituril by an ester bond.
[0051] Preferably, a cucurbituril derivative-bonded solid substrate according to the present
invention is further subjected to drying and purification after being sufficiently
washed with water and an organic solvent to remove residual impurities.
[0052] The present invention also provides a protein chip including the cucurbituril derivative-bonded
solid substrate. Cucurbituril has carbonyl groups on the entrance of its cavity, and
thus, can retain various ionic compounds such as organic cations and high polarity
compounds by charge-polarity interactions, polarity-polarity interactions, or hydrogen
bonds. In particular, cucurbituril is bonded to diaminoalkane salt by a coupling constant
of about 10
6 M
-1, which is smaller than that of avidin-biotin interaction but is larger than that
of a common non-covalent bond such as a coordination bond or a hydrogen bond. Therefore,
a protein chip including the cucurbituril derivative-bonded solid substrate has advantages
such as low manufacturing costs, a strong coupling constant, and immobilization of
proteins on a solid substrate without damage to active sites of the proteins.
[0053] In addition, the cucurbituril derivative-bonded solid substrate of the present invention
is covalently bonded to genes or biomaterials, and thus, can be used in preparation
of a gene chip and a sensor for biomaterial assay.
Effect of the Invention
[0054] As apparent from the above description, a cucurbituril derivative-bonded solid substrate
according to the present invention enables immobilization of proteins on a surface
of the solid substrate via a non-covalent bond with a very strong coupling constant
Based on this property of the solid substrate, a protein chip with no damage to active
sites of proteins can be prepared in a cost-effective manner.
[0055] FIG. 3 is a diagram that illustrates a cucurbituril derivative-covalent bonded solid
substrate.
BEST MODE FOR CARRYING OUT THE INVENTION
[0056] Hereinafter, the present invention will be described more specifically by Example.
However, the following Examples are provided only for illustrations and thus the present
invention is not limited to or by them.
Example 1: Preparation of cucurbituril derivative-bonded solid substrate
[0057] A glass substrate was washed with a piranha solution (a 3:1 mixture of sulfuric acid
and hydrogen peroxide) to introduce a hydroxyl group to a surface of the glass substrate,
sufficiently dried under a reduced pressure, and added in a 20 ml vial under a nitrogen
atmosphere. Then, a 10 mM solution of (3-mercaptopropyl)triethoxysilane in toluene
was added thereto and incubated at room temperature to perform silanization. After
the silanization was completed, the glass substrate was washed with toluene and heated
at 120°C under a reduced pressure for one hour. The glass substrate was placed in
a crystal tube, and a solution of 10 mg allyloxycucurbit[6]uril of Formula 1 where
R
1 is an allyloxy group in a 1:1 mixed solvent of chloroform and methanol was added
thereto. The reaction mixture underwent oxygen removal by the supply of nitrogen in
the crystal tube and then exposed to ultraviolet light with a wavelength of 300 nm
for 38 hours. After the reaction terminated, the resultant glass substrate was sequentially
washed with dimethylsulfoxide, dimethylformamide, chloroform, methanol, and acetone,
and dried under a reduced pressure.
Example 2: Preparation of cucurbituril derivative-bonded solid substrate
[0058] A glass substrate was washed with a piranha solution to introduce a hydroxyl group
to a surface of the glass substrate, sufficiently dried under a reduced pressure,
and added in a 20 ml vial under a nitrogen atmosphere. Then, a 10 mM solution of (3-aminopropyl)triethoxysilane
in toluene was added thereto and incubated at room temperature to perform silanization.
After the silanization was completed, the glass substrate was washed with toluene
and heated at 120°C under a reduced pressure for one hour. 10 mg of carboxymethylsulfinylpropyloxycucurbit[6]uril
of Formula 1 where R
1 is a carboxymethylsulfinylpropyloxy group was dissolved in 10 mL of dimethylformamide,
and 150 mg of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDAC) and
3 mg of N-hydroxysuccinimide were then added thereto. The amino-modified glass substrate
was placed in the resultant solution and stirred at room temperature for 12 hours.
After the reaction terminated, the resultant glass substrate was sequentially washed
with dimethylformamide, methanol, water, and acetone, and dried under a reduced pressure.
Example 3: Preparation of cucurbituril derivative-bonded solid substrate
[0059] A glass substrate was washed with a piranha solution to introduce a hydroxyl group
to a surface of the glass substrate, sufficiently dried under a reduced pressure,
and added in a 20 ml vial under a nitrogen atmosphere. Then, a 10 mM solution of (3-aminopropyl)triethoxysilane
in toluene was added thereto and incubated at room temperature to perform silanization.
After the silanization was completed, the glass substrate was washed with toluene
and heated at 120°C under a reduced pressure for one hour. The resultant amino-modified
glass substrate was immersed in a solution of 100 mg of succinic anhydride in diemethylformamide
and stirred at room temperature for 12 hours. After the reaction terminated, the glass
substrate was sequentially washed with dimethylformamide, water, methanol, and acetone,
and dried under a reduced pressure. 10 mg of aminocucurbit[6]uril of Formula 1 where
R
1 is an amino group was dissolved in 10 mL of dimethylformamide, and 150 mg of EDAC
and 3 mg of N-hydroxysuccinimide were then added thereto. Then, the glass substrate
was placed in the resultant solution and stirred at room temperature for 12 hours.
After the reaction terminated, the resultant glass substrate was sequentially washed
with dimethylformamide, methanol, water, and acetone, and dried under a reduced pressure.
Example 4: Preparation of cucurbituril derivative-bonded solid substrate
[0060] A glass substrate was washed with a piranha solution to introduce a hydroxyl group
to a surface of the glass substrate, sufficiently dried under a reduced pressure,
and added in a 20 ml vial under a nitrogen atmosphere. Then, a 10 mM solution of (3-glycidoxypropyl)triethoxysilane
in toluene was added thereto and incubated at room temperature to perform silanization.
After the silanization was completed, the glass substrate was washed with toluene
and heated at 120°C under a reduced pressure for one hour. 10 mg of 2-hydroxyethyloxycucurbit[6]uril
of Formula 1 where R
1 is a 2-hydroxyethyloxy group and the resultant glycidoxy-modified glass substrate
were placed in 10 mL of dimethylformamide. Then, a catalytic amount of boron trifluoride
(BF
3) and diethylether (Et
2O) were added thereto and stirred at room temperature for two hours, followed by further
stirring at 85°C for 12 hours. After the reaction terminated, the resultant glass
substrate was sequentially washed with dimethylformamide, chloroform, methanol, water,
and acetone, and dried under a reduced pressure.
Example 5: Preparation of cucurbituril derivative-bonded solid substrate
[0061] A glass substrate was washed with a piranha solution to introduce a hydroxyl group
to a surface of the glass substrate, sufficiently dried under a reduced pressure,
and added in a 20 ml vial under a nitrogen atmosphere. Then, a 10 mM solution of (3-glycidoxypropyl)triethoxysilane
in toluene was added thereto and incubated at room temperature to perform silanization.
After the silanization was completed, the glass substrate was washed with toluene
and heated at 120°C under a reduced pressure for one hour. 10 mg of 2-aminoethytoxycucurbit[6]uril
of Formula 1 where R
1 is a 2-aminoethyloxy group and the resultant glycidoxy-modified glass substrate were
placed in a phosphate buffer (pH 8.8) and stirred for 12 hours. After the reaction
terminated, the resultant glass substrate was immersed in 10 mL of 0.2N HCl solution,
stirred for 30 minutes, sequentially washed with water, acetone, and methanol, and
dried under a reduced pressure.
Examples 6: Preparation of cucurbituril derivative-bonded solid substrate
[0062] A gold-deposited silicon wafer was washed with a piranha solution, sufficiently dried
under a reduced pressure, and added in a 20 ml vial under a nitrogen atmosphere. Then,
a 1 mM solution of 1,8-octanedithiol in ethanol was added thereto and incubated at
room temperature to obtain a thiol-modified gold substrate. The thiol-modified gold
substrate (in Formula 2, R
2 is a propylthiol group) was placed in a test tube and a solution of allyloxycucurbit[6]uril
of Formula 1 where R
1 is an allyloxy group in 5 mL of a 1:1 mixed solvent of chloroform and methanol was
added thereto. The reaction mixture underwent oxygen removal by the supply of nitrogen
in the test tube and then exposed to ultraviolet light with a wavelength of 300 nm
for 36 hours. After the reaction terminated, the resultant gold substrate was sequentially
washed with dimethylsulfoxide, dimethylformamide, chloroform, methanol, and acetone,
and dried under a reduced pressure.
Example 7: Preparation of cucurbituril derivative-bonded solid substrate
[0063] A gold-deposited silicon wafer was washed with a piranha solution, sufficiently dried
under a reduced pressure, and added in a 20 ml vial under a nitrogen atmosphere. Then,
a 1 mM solution of 2-aminoethanediol in ethanol was added thereto and incubated at
room temperature to obtain an amino-modified gold substrate. 10 mg of carboxymethylsulfinylpropyloxycucurbit[6]uril
of Formula 1 wherein R
1 is a carboxymethylsulfinylpropyloxy group was dissolved in 10 mL of dimethylformamide,
and 150 mg of EDAC and 3 mg of N-hydroxysuccinimide were added thereto. The amino-modified
gold substrate was added to the resultant solution and stirred at room temperature
for 12 hours. After the reaction terminated, the gold substrate was sequentially washed
with dimethylformamide, methanol, water, and acetone, and dried under a reduced pressure.
Example 8: Preparation of cucurbituril derivative-bonded solid substrate
[0064] A gold-deposited silicon wafer was washed with a piranha solution, sufficiently dried
under a reduced pressure, and added in a 20 ml vial under a nitrogen atmosphere. Then,
a 1 mM solution of 11-mercaptoundecanoic acid in ethanol was added thereto and incubated
at room temperature to obtain a carboxyl-modified gold substrate. The carboxyl-modified
gold substrate was immersed in a solution of 100 mg of succinic anhydride in dimethylformamide
and stirred at room temperature for 12 hours. 10 mg of aminocucurbit[6]uril of Formula
1 wherein R
1 is an amino group was dissolved in 10 mL of dimethylformamide, and 150 mg of EDAC
and 3 mg of N-hydroxysuccinimide were added thereto. The carboxyl-modified gold substrate
was added to the resultant solution and stirred at room temperature for 12 hours.
After the reaction terminated, the resultant gold substrate was sequentially washed
with dimethylformamide, methanol, water, and acetone, and dried under a reduced pressure.
Example 9: Preparation of cucurbituril derivative-bonded solid substrate
[0065] A gold-deposited silicon wafer was washed with a piranha solution, sufficiently dried
under a reduced pressure, and added in a 20 ml vial under a nitrogen atmosphere. Then,
a 1 mM solution of 11-mercaptoundscanoic acid in ethanol was added thereto and incubated
at room temperature to obtain a carboxyl-modified gold substrate. The gold substrate
was immersed in 10 mL of anhydrous diemethylformamide under a nitrogen atmosphere,
and 100 µℓ of N-methylmorpholine and 100 µℓ of ethylchloroformate were sequentially
added thereto, followed by stirring for 24 hours. After the reaction terminated, the
gold substrate was several times washed with diethylether and dried under a reduced
pressure. 10 mL of anhydrous dimethylformamide was added to the gold substrate and
10 mL of 2-hydroxyethyloxycucurbit[6]uril of Formula 1 wherein R
1 is a 2-hydroxyethyloxy group under a nitrogen atmosphere and stirred for 24 hours.
After the reaction terminated, the gold substrate was sequentially washed with dimethylformamide,
water, methanol, and acetone, and dried under a reduced pressure.
[0066] While the above Examples has been particularly shown and described in terms of only
specific bonds between cucurbituril and a solid substrate, it will be understood by
those of ordinary skill in the art that synthesis of a solid substrate linked with
cucurbituril is possible by various types of bonds.