Peculiarities of glucose oxidase adsorption by mesoporous aluminosilicates synthesized in presence of biotemplates
A study of glucose oxidase adsorption has been undertaken from a solution of the enzyme (0.125 mmol dm⁻³) in acetate buffer (pH 4) onto mesoporous aluminosilicates synthesized in the presence of biomolecules (lecithin, glucose oxidase). These aluminosilicates displays a high sorption capacity (up to...
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Smelaya, Z.V. Goltsov, Yu.G. 2017-11-20T18:43:36Z 2017-11-20T18:43:36Z 2002 Peculiarities of glucose oxidase adsorption by mesoporous aluminosilicates synthesized in presence of biotemplates / Z.V. Smelaya, Yu.G. Goltsov // Поверхность. — 2002. — Вип. 7-8. — С. 134-142. — Бібліогр.: 17 назв. — англ. XXXX-0106 https://nasplib.isofts.kiev.ua/handle/123456789/126360 A study of glucose oxidase adsorption has been undertaken from a solution of the enzyme (0.125 mmol dm⁻³) in acetate buffer (pH 4) onto mesoporous aluminosilicates synthesized in the presence of biomolecules (lecithin, glucose oxidase). These aluminosilicates displays a high sorption capacity (up to 150 mg/g). The physical adsorption of the enzyme showed clear dependence on pore diameter of the materials. The porous structure of such inclusion compounds was detailed. The glucose oxidase cannot be removed from the aluminosilicates with repeated washing in the acetate buffer. en Інститут хімії поверхні ім. О.О. Чуйка НАН України Поверхность Surface chemistry of silica and related sorbents Peculiarities of glucose oxidase adsorption by mesoporous aluminosilicates synthesized in presence of biotemplates Article published earlier |
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Peculiarities of glucose oxidase adsorption by mesoporous aluminosilicates synthesized in presence of biotemplates |
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Peculiarities of glucose oxidase adsorption by mesoporous aluminosilicates synthesized in presence of biotemplates Smelaya, Z.V. Goltsov, Yu.G. Surface chemistry of silica and related sorbents |
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Peculiarities of glucose oxidase adsorption by mesoporous aluminosilicates synthesized in presence of biotemplates |
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Peculiarities of glucose oxidase adsorption by mesoporous aluminosilicates synthesized in presence of biotemplates |
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Peculiarities of glucose oxidase adsorption by mesoporous aluminosilicates synthesized in presence of biotemplates |
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Peculiarities of glucose oxidase adsorption by mesoporous aluminosilicates synthesized in presence of biotemplates |
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peculiarities of glucose oxidase adsorption by mesoporous aluminosilicates synthesized in presence of biotemplates |
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Smelaya, Z.V. Goltsov, Yu.G. |
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Smelaya, Z.V. Goltsov, Yu.G. |
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Surface chemistry of silica and related sorbents |
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Surface chemistry of silica and related sorbents |
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2002 |
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English |
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Інститут хімії поверхні ім. О.О. Чуйка НАН України |
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A study of glucose oxidase adsorption has been undertaken from a solution of the enzyme (0.125 mmol dm⁻³) in acetate buffer (pH 4) onto mesoporous aluminosilicates synthesized in the presence of biomolecules (lecithin, glucose oxidase). These aluminosilicates displays a high sorption capacity (up to 150 mg/g). The physical adsorption of the enzyme showed clear dependence on pore diameter of the materials. The porous structure of such inclusion compounds was detailed. The glucose oxidase cannot be removed from the aluminosilicates with repeated washing in the acetate buffer.
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XXXX-0106 |
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https://nasplib.isofts.kiev.ua/handle/123456789/126360 |
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Peculiarities of glucose oxidase adsorption by mesoporous aluminosilicates synthesized in presence of biotemplates / Z.V. Smelaya, Yu.G. Goltsov // Поверхность. — 2002. — Вип. 7-8. — С. 134-142. — Бібліогр.: 17 назв. — англ. |
| work_keys_str_mv |
AT smelayazv peculiaritiesofglucoseoxidaseadsorptionbymesoporousaluminosilicatessynthesizedinpresenceofbiotemplates AT goltsovyug peculiaritiesofglucoseoxidaseadsorptionbymesoporousaluminosilicatessynthesizedinpresenceofbiotemplates |
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1850578632730214400 |
| fulltext |
134
PECULIARITIES OF GLUCOSE OXIDASE
ADSORPTION BY MESOPOROUS ALUMINOSILICATES
SYNTHESIZED IN PRESENCE OF BIOTEMPLATES
Z.V. Smelaya and Yu.G. Goltsov
L.V. Pisarzhevsky Institute of Physical Chemistry, National Academy of Sciences
Pr. Nauky 31, 03039 Kyiv, UKRAINE
Abstract
A study of glucose oxidase adsorption has been undertaken from a solution of the
enzyme (0.125 mmol dm-3) in acetate buffer (pH 4) onto mesoporous aluminosilicates
synthesized in the presence of biomolecules (lecithin, glucose oxidase). These
aluminosilicates displays a high sorption capacity (up to 150 mg/g). The physical adsorption
of the enzyme showed clear dependence on pore diameter of the materials. The porous
structure of such inclusion compounds was detailed. The glucose oxidase cannot be removed
from the aluminosilicates with repeated washing in the acetate buffer.
Introduction
Mesoporous silicates and aluminosilicates applied to biological systems open many
potential applications due to their large, controllable pore sizes, high internal surface areas,
chemical inertness and the ability to modify their surfaces. Some general areas where such
materials could be applied are in the separation of proteins or other large biochemical
molecules, and as supports for biocatalytic systems and in biosensor application [1-6]. They
provide many advantages over conventional dextran polymer and sol-gel based
immobilization techniques, the most significant being their highly ordered rigid structures and
their resistance to microbial attack due to their inert inorganic nature. Mesoporous silicates
and aluminosilicates possess tunable narrow pore size distribution in the range of 1.5-12 nm.
These dimensions are of the same size as proteins and other biomolecules and thus makes
such solids attractive candidates to host encapsulated/immobilized enzymes.
Balkus et al [4-6] has immobilized cytochrome c, papain and trypsin onto MCM-41,
SBA-15 and layered niobium oxide NB-TMS4. They have shown that the physical adsorption
process is dependent on pH of the adsorption buffer and the pore size of the material. For
instance peroxidase adsorption onto MCM-41 was limited due to the enzyme being larger
than the pore diameters [5]. In more recent study it has been established that immobilized
cytochrome c is stable under what would normally be denaturing conditions and cyclic
voltammetry has shown cytochrome c to be active for several months [6]. Adsorption and
desorption characteristics of cytochrome c onto different ordered mesoporous silicates have
been detailed in [1]. Adsorbed protein was not desorbed with repeated washing in buffer but
polyethylene glycol and/or ammonium sulfate in buffer caused considerable desorption.
Glucose oxidase (GO) is the most widely used enzyme in the field of biosensors. However,
the efficiency of the glucose sensors is limited, mainly due to the heterogeneity of the enzyme
distribution in the biosensor membrane, which makes difficult the creation of the effectively
functioning compact analytical devices [7]. In order to improve the molecular architecture of
135
the biosensor the approach of using of ordered mesoporous materials with tunable narrow
pore size distribution might be fruitful.
Recent studies indicate that a biomimetic approach based on the main constructional
processes of biomineralization results in the development of new strategies in controlled
synthesis of high ordered inorganic materials. Imitation of the basic processes of
biomineralization - super molecular preorganization (formation of organic matrices by spatial
organization of an assembly of macromolecules) and molecular recognition (templating) -
permits the preparation of valuable products under relatively mild conditions, the regulation
of structure formation, and also exclusion of the use of toxic intermediates [8-9]. Variation in
the nature of the templates used for mineralization and also the composition of the reaction
mixture may permit materials, which differ in the size of the pores, the nature of the active
sites, the composition of the skeleton and other characteristics of the porous substances
suitable for the inclusion of various macromolecules and their ensembles [10-11].
In this paper the results of a study of the adsorption of glucose oxidase onto
mesoporous aluminosilicates synthesized in the presence of biotemplates (lecithin, GO) are
described. Glucose oxidase is dimer of ca. 160 000 molecular weight, containing two identical
and no interacting flavin groups [12-13]. The isoelectric point of the native GO is 4.44 [14].
According to X-ray crystallography data [14] the dimeric partially deglycosylated GO
molecule is compact spheroid with approximate dimensions 6.0´5.2´7.7 nm. It has been
found with the use of dynamic light scattering that the hydrodynamic diameter of the native
GO molecule is 7.6 nm [14]. This value corresponds to a molecular cross section area of
about 45 nm2. At cubic packing of the protein in a surface monolayer, the area occupied by
one molecule is about 58 nm2.
Experimental
Aluminosilicate МСМ-41 materials were synthesized by using sodium silicate,
aluminum sulfate, and cetyltrimethylammonium bromide (СТМАВ). The compositions of the
reaction mixtures were: 16.2SiO2:Аl2O3:5.4Na2O:13.8СТМАВ:1767Н2O (sample SA2, рН of
the reaction mixture was close to neutral) and 116SiO2:Аl2O3:38Na2O:49СТМАВ: 9101Н2O
(sample SA1, рН»9). The hydrothermal synthesis was carried out at 423K for 48 h. The
obtained product was washed with water, dried in air and calcined at 823K for 6 h in
air [10-11].
Aluminosilicate mesoporous materials in the presence of lecithin (L) were synthesized
by adding lecithin (17% of L-a-phosphatidyl choline, Sigma) or its combinations with
СТМАВ or octadecylamine (ODA) instead of СТМАВ to the reaction mixture, so that the
L:СТМАВ and L:ОDА molar ratios in a reaction mixture were 0.47 or 1.40 and 0.34 or 1.04,
respectively. The hydrothermal synthesis was carried out at 353K for 72 h. The obtained
products were washed with water, dried in air and calcined at 823K for 6 h in air [10].
Aluminosilicate mesoporous materials in the presence of GO were synthesized from
the reaction mixture of sample SA2. Glucose oxidase (from Aspergillus niger, Sigma) was
added to the reaction mixture (1) without changing the amount of CTMAB in the mixture so
that the mass ratio of GO:CTMAB=0.5 (sample SA2-G01) (2) without changing the overall
amount of template in the mixture, i.e., GO replaced part of the CTMAB so that the mass
ratio GO:CTMAB=0.25 (sample SA2-G02). The hydrothermal synthesis was carried out at
423K for 48 h. The obtained product was washed with water, dried in air and calcined at
823K for 6 h in air [11].
The Si:Al ratios in the samples were close to them in the reaction mixtures.
136
The sorption of glucose oxidase on obtained mesoporous aluminosilicates was carried
out from acetate buffer of pH=4 (0.02 g GO per 1 ml of buffer; 0.08 g of sorbent per 1 ml of
solution) at 35°C over a period of 20 h. The samples produced were washed repeatedly
(5 times) by water, then by adsorption acetate buffer and by water, and dried in air. The
GO1-SA2-L2 sample was additionally washed by 0.5 M NaCl solution. The amount of
adsorbed protein was calculated from the difference between the protein concentrations in the
supernatants before GO adsorption and after washing procedure. The protein concentration in
solutions was determined by spectrophotometric monitoring of absorption at 36000 cm-1
(Specord UV VIS).
The characterization of samples was carried out by the powder X-ray diffraction
(automatic diffractometer DRON-ЗМ, СuKa radiation) and methanol ad(de)sorption
measurements at 293K on standard vacuum set-up based on the McBain-Backr quartz spring
balance (prior to measurements mesoporous samples were degassed at 390К, samples
containing GO were degassed at 303К). The Kelvin equation (assuming hemispherical
meniscus and zero contact angle) with the multilayer thickness correction was applied to
determine the pore diameter distribution [15]. Total volume VS of the samples were estimated
from the isotherms at p/ps=0.95 assuming that the pores have been filled with condensed
liquid adsorptive. The BET surface area SBET was calculated in the conventional manner, the
methanol molecule area was accepted to be 25 Å2.
Results and discussion
Peculiarities of the porous structure of mesoporous aluminosilicates (MPAS)
synthesized in the presence of biomolecules have been analyzed in our earlier studies [10-11].
Mesoporous SA2-GO1 and SA2-GO2 samples with complex porous structure were obtained
in the presence of combination GO:CTMAB=0.5 and 0.25 (Si:Al=8). Both samples have
similar isotherms (Fig. 1) with four hysteresis loops, which begin and end at similar values of
p/ps and 3 peaks corresponding 3 effective sizes of mesopores in the 3.0-10.0 nm range
(Table 1) is observed on the pore size distributions. The sample SA2-GO2 obtained in the
presence of GO:CTMAB=0.25 exhibits a wider pore size distribution [11].
It was shown [10-11] that in the presence of only lecithin mesoporous substances are
formed, so the supramolecular structures of lecithin molecules are template in aluminosilicate
framework formation. We have found that MPAS with pore diameters up to 10.0 nm and
biporous materials, which have bimodal mesopore size distribution, can be prepared in the
presence of the lecithin mixtures with CTAB or ODA (Fig. 2, Table 1) as template.
The adsorption of GO onto MPAS likely involves numerous interactions between the
support surface and the exterior amino acid residues of the protein. These interactions can
depend on the composition of the MPAS and the tertiary structure of the protein. The presence
of negative charge sites in MPAS can promote adsorption through electrostatic forces through
positively (below the isoelectric point) charged amino acid residues on the enzyme. Many
hydrophilic side chains, as well as covalently bound polysaccharide chains of the native
glycoprotein GO molecule are located on its surface [12, 14]. Therefore, hydrogen bonding to
surface hydroxyl groups can also influence on enzyme adsorption, as it has been described for
adsorption of the enzyme onto platinum [16]. The high amount of adsorbed protein for the all
MPAS used indicates that the GO adsorption strongly influenced by hydrophobic/hydrophilic
interactions rather than electrostatically in agreement with [4].
The greatest GO sorption capacity possess MPAS with greatest total adsorption
volume (Si:Al=58, samples SA1-L3 and SA1-L5 synthesized in presence L:CTMAB=.40 and
L:ODA=1.04 respectively). As shown in [10-11], such materials have mesopores of large size
(D=8.0 nm and D=11.4 nm, accordingly) and identical, most likely, of channel constitution.
137
The larger part of adsorption volume (approximately 70 and 80 %, accordingly) corresponds
to the pores with D>8.0 nm (the dynamic diameter of GO molecule). The SA1-L5 material
also has sub-group of pores of sizes ranging from 20-50 nm with very small, compared with
pores D=11.4 nm, adsorption volume. Such sample (Table 2) adsorbs about 130 mg/g of GO.
After GO adsorption, the total adsorption volume of the SA1-L5 material is reduced in
1.7 times, but adsorption volume of pores with D<8.0 nm does not vary.
Fig. 1. Methanol ad(de)sorption isotherms and pore size distributions
for samples SA1-GO1 (1) and SA2-GO2 (2).
Table 1. Peculiarities of the porous structure of mesoporous aluminosilicates synthesized in
the presence of biotemplates.
Mesoporous
aluminosilicate
Si:Al1 Template D,
nm
DD,
nm
V0.78
2
,
cm3/g
VS,
cм3/g
SBET,
m2/g
SA1-L3 58 L:CTMAB=1.40 8.0 2.5÷15.0 0.40 1.33 342
SA1-L5 58 L:ODA=1.04 5.8
11.4
2.5÷7.5
7.5÷17.5
0.22 1.23 256
SA2-L2 8.1 L:CTMAB=0.47 3.6
9.8
2.0÷5.0
7.5÷12.5
0.46 0.77 342
SA2-GO1 8.1 GO:CTMAB=1:2 3.1
4.5
8.1
2.5÷3.8
3.8÷4.6
6.2÷10.6
0.58 0.84 775
SA2-GO2 8.1 GO:CTMAB=1:4 2.7
4.2
6.8
2.5÷3.8
3.8÷5.0
5.5÷9.0
0.43 0.63
544
1 The Si:Al ratio in reaction mixture.
2 Adsorption volume of pores with D<8.0 nm.
138
The sorption of GO onto sample SA1-L3 occurs in the same manner. Such material
exhibited wide pore size distribution (DD=2.5-15.0 nm) with the maximum at D=8.0 nm, the
considerable part of adsorption volume is in the pores with sizes ranging from 6.0-10.0 nm.
After a sorption GO (151 mg/g) adsorption volume of the pores with D<8.0 nm, does not
change, and the considerable part of adsorption volume is in pores with sizes ranging from
4.0-6.0 nm, the pores with D>6.5 nm practically disappear.
Fig. 2. Methanol ad(de)sorption isotherms for samples SA2-L2 (2), SA1-L5 (6) and
synthesized in the presence of L, Si:Al=8 (1), L:ODA=0.34, Si:Al=8 (3),
L:CTMAB=0.47, Si:Al=58 (4), L, Si:Al=8 (5); and pore size distributions for
samples SA2-L2 (1), SA1-L5 (5) and synthesized in the presence of
L:CTMAB=0.47, Si:Al=58 (2), L, Si:Al=8 (3), L:ODA=0.34, Si:Al=8 (4).
From such data it appears that the protein molecules penetrate into pore network, so
the adsorption onto SA1-L3 and SA1-L5 occurs onto internal surface of the support. The
protein loaded MPAS samples are characterized by similar type IV isotherms (Fig. 3) with
wide H1 hysteresis ranging from р/ps=0.2-0.9. However the isotherms of the GO1-SA1-L3
and GO1-SA1-L5 exhibit much shaper increase of adsorbed methanol volume, than isotherms
of other protein loaded MPAS. In addition, such increase is displaced towards the high
relative pressure and occurs for relative pressure р/ps greater than 0.6. The analysis of
adsorption data allows assuming, that along to cylindrical or hexagonal pores protein loaded
MPAS materials contain some amount of bottle shaped pores. It is known [17] that the
relationships between the relative pressure ha, of the adsorption branch and the relative
pressure hd of desorption branch corresponding to equal adsorbed amounts, differ for different
shapes of pores. Thus, for instance, for the model of cylindrical open-ended pores ha
2=hd. The
relation that applies to model pore structures containing bottle shaped pores with narrow
139
throats the cavity radius of which is more than double the throat radius, is the inequality
ha
2>hd. For bottle shaped pores the effective cavity radius of which is less than double the
effective throat radius, and for tubular pores with the same ratio of the two principal
dimensions, the inequality changes to ha
2<hd. Graphical representation of the dependence of
ha
2 on hd. is a convenient means for studying the dependence of the shape of pores on their
dimensions. As we can see from Fig. 4, all samples obtained after GO sorption contain bottle
shaped pores with cavity radius larder than the throat diameter. The pores of such type can be
formed owing to the GO sorption in the case if the difference between the pore size of the
support and GO molecular diameter is greater than kinetic diameter of methanol molecule
(0.33 nm [15]). Therefore methanol molecules can penetrate the pores of protein loaded
MPAS.
Table 2. Peculiarities of the porous structure of mesoporous aluminosilicates synthesized
in the presence of biotemplates after GO sorption.
Mesoporous
aluminosilicate
after GO
sorption
Amount of
GO
adsorbed,
mg/g
D,
Nm
DD,
nm
V0.78
1,
cm3/g
VS,
cm3/g
SBET,
m2/g
GO1-SA1-L5 130 5.0 3.0÷7.0 0.22 0.71 210
GO1-SA1-L3 151 4.9 3.5÷6.5 0.39 0.89 336
GO1-SA2-L2 66
(60)2
4.1
(4.1)2
2.0÷8.0
(2.0÷8.0)2
0.35
(0.43)2
0.69
(0.70)2
502
(570)2
GO1-SA2-GO1 42 - Up to 8.0 nm 0.34 0.71 498
GO1-SA2-GO2 69 4.5 2.5÷7.0 0.36 0.59
462
1 Adsorption volume of pores with D<8.0 nm.
2 The characteristics of sample after washing by 0.5 M NaCl solution.
Fig. 3. Methanol ad(de)sorption isotherms for samples GO1-SA1-L5 (1),
GO1-SA2-L2 (2) and pore size distributions for samples GO1-SA2-L2 (1),
GO1-SA2-GO2 (2), GO1-SA1-L3 (3).
140
Fig. 4. The dependence of ha
2 on hd for samples GO1-SA2-L2, GO1-SA1-L3, GO1-SA1-L5,
GO1-SA2-GO1 and for sample GO1-SA2-L2 after washing by 0.5 M NaCl solution.
The adsorbed GO was found to be stable on the MPAS materials after repeated
washings in adsorption buffer and water. The protein was washed repeatedly (5 times) with
UV-scans detecting no protein in the supernatant solution. The difficulty of desorption may be
explained by low probability of such process due to “multipoint” bonding of protein globule
with support interface while the desorption requires simultaneous rupture of all bonds (this
corresponds to a considerable difference between the activation energies for the adsorption
and desorption processes).
The washing up 0.5 М NaCl solution also almost does not influence on porous
structure of a sample GO1-SA10-L2 (Table 2). However, the analysis of dependence (ha)2 on
hd demonstrates that the washing by 0.5 М NaCl solution results in disappearing of bottle
shaped pores with narrow throats (Fig. 4).
The calculation according to Kelvin equation from desorption branch of the isotherm
demonstrates that the GO1-SA1-L3, GO1-SA1-L5 samples are characterized by relative
narrow throat size distributions with the peak at diameter D=5.0 nm, regardless of porous
structure of the source MPAS materials (Table 2). Total adsorption volume of the samples is
rather large (0.72, 0.88 см3/g, accordingly), but considerably smaller than total adsorption
volumes of source mesoporous materials, and the adsorption volume of mesopores of
diameter ranging from 3.0 nm up to 7.0 nm is about 60% of total adsorption volume. The
pores with D>8.0 nm are practically absent. It seems to indicate that GO molecules fill almost
all pores, which being large enough to accommodate them. The size of filled pores is
diminished on the magnitude of GO molecular diameter, so the source MPAS with
homogeneous large pores change to bottle shaped pores material with narrow neck size
distributions.
SA2-L2, SA2-GO1 and SA2-GO2 (see Table 1) possess complex porous structure and
the pores with D>8.4 nm have considerably smaller adsorption volume in comparison with
SA1-L3 and SA1-L5. Thereof SA2-L2, SA2-GO1 and SA2-GO2 have smaller GO sorption
141
capacity (66, 42 and 69 mg/g, respectively). After GO adsorption such MPAS exhibit wide
pore size distributions ranging from 2.0-8.0 nm (Fig. 3, Table 2).
A decrease in surface area was measure for the protein loaded MPAS. Significantly
lower surface area measured for the protein loaded GO1-SA2-GO1 and GO1-SA2-GO2,
while that determined for the GO1-SA1-L3 and GO1-SA1-L5 was slightly smaller. Such
results may be explained if it is supposed that the different sub-groups of the MPAS are
interconnected. This is also supported by the considerable decrease of methanol adsorption
volume of pores with D<8 nm for such MPAS after GO adsorption.
The protein loading and MPAS surface area before protein adsorption provide an
opportunity to estimate the enzyme coverage. A monolayer of GO would consist of
approximately 4.4×1018 molecules for SA1-L5 (in the case of cubic packing). This value is
very close to that calculated from the GO loading of 4.9×1017 for this MPAS. Such surface
concentration of the protein corresponds to molecular cross section area 523 nm2, whereas
maximum surface concentration of the GO at silicas is characterized by molecular cross
section areas ranging from 800 nm2 [14]. These results may encourage the application of such
protein adsorbed MPAS materials as active elements of biosensors or sorbents for
biomolecular sorption.
Conclusions
Studies of glucose oxidase sorption onto mesoporous aluminosilicates synthesized in
the presence of biotemplates (lecithin, glucose oxidase) indicate that these sorbents possess
high sorption capacity. The amount of adsorbed glucose oxidase is related to the
characteristics of the mesopore diameter with most adsorption associated with materials
having pore diameter in excess of the size of glucose oxidase molecule. The inclusion
compounds of adsorbent-glucose oxidase type based on mesoporous aluminosilicates with
large pores and great total adsorption volume (up to 1.3 cm3/g) have the biggest content of
glucose oxidase (up to 150 mg/g). The sorption of glucose oxidase occurs within the pores of
effective diameter exceeding that of protein (8 nm) and results in essential reduction of
methanol adsorption volume. Porous structure of such inclusion compounds is characterized
by a narrow distribution of pore sizes with effective diameter at 5 nm. The inclusion
compounds based on mesoporous aluminosilicates with small total adsorption volume (up to
0.8 cm3/g), the larger part of the latter corresponding to the pores with a diameter ranging
down to 8 nm, exhibit broad distribution of pore sizes and smaller content of glucose oxidase
(up to 70 mg/g).
The results obtained allow us to consider aluminosilicate mesoporous materials
synthesized in the presence of biotemplates as a prospect for creation of high capable and
selective sorbents for biomolecular sorption or active elements of chemical and biosensors.
References
1. Deere J., Magner E., Wall J.G., and Hodnett B. K. Adsorption of cytochrome c onto
ordered mesoporous silicates // Studies in Surface Sci. and Catal. - 2001. - V.135. -
A23P17 (CD version).
2. Han Y.-J., Margolese D., Stucky G.D., and Butler A. Protein extraction by
mesoporous materials // Abstr. Pap. Amer. Chem. Soc. - 1999. - V.217. - P.220.
3. Han Y.-J., Stucky G.D., and Butler A. Mesoporous silicate sequestration and
release of proteins // J. Am. Chem. Soc. - 1999. - V.121, N42. - P.9897-9898.
142
4. Gimon-Kinsel M.E., Jimenez V.L., Washmon L., and Balkus K.J. Mesoporous
molecular immobilized enzymes // Studies in Surface Sci. and Catal. - 1998. -
V.117. - P.373-380.
5. Diaz J.F., and Bulkus K.J. Enzyme immobilization in MCM-41 molecular sieve //
J. Mol. Catal. B-Enzym. - 1996. - V.2, N2-3. - P.115-126.
6. Washmon L., Gimon-Kinsel M.E., and Bulkus K.J. Mesoporous molecular sieve
thin films for enzyme immobilization // Abstr. Pap. Amer. Chem. Soc. - 1999. -
V.215. - P.340.
7. Pickup J.C. and Thevenot D.R. Advances in Biosensors. London: JAI, 1993.
8. Mann S., Archibald D.D., Didymus J.M., Douglas T., Heywood B.R.,
Meldrum F.C. and Reeves N.J. Crystallization at inorganic-organic interfaces:
biominerals and biomimetic synthesis // Science. - 1993. - V.261, N5126. -
P.1286-1292.
9. Mann S. Molecular tectonics in biomineralization and biomimetic materials
chemistry // Nature. - 1993. - V.365, N6446. - P.499-505.
10. Goltsov Y.G., Matkovskaya L.A., Smelaya Z.V., and Il’in V.G. Preparation of
mesoporous aluminosilicates in the presence of lecithin: a simulation of
biomineralization processes // Mendeleev Commun. - 1999. – N6. - P.241-243.
11. Smelaya Z.V., Matkovskaya L.A., and Goltsov Y.G. Peculiarities of the porous
structure of alumonosilicate mesoporous substances obtained in the presence of
biotemplates // J. Therm. Anal. Cal. - 2000. - V.62. - P.443-450.
12. Frederick K. R., Tung J., Emerick R. S., Masiarz F.R., Chamberlain S.H.,
Vasavada A., and Rosenberg S. Glucose oxidase from Aspergillus niger // J. Biol.
Chem. - 1990. - V. 265, N 7. - P.3793-3802.
13. Bourdillon C., Demaille C., Moiroux J., and Savéant J.-M. New insights into the
enzymatic catalysis of the oxidation of glucose by native and recombinant glucose
oxidase mediated by electrochemically generated one-electron redox cosubstrates
// J. Am. Chem. Soc. - 1993. - V.115. - P.2-10.
14. Kamyshny A., Feldman A., Baszkin A., Boissonnade M.M., Rosilio V., and
Magdassi S. Chemically modified glucose oxidase with enhanced hydrophobicity:
adsorption at polystyrene, silica and silica coated by lipid monolayers // J. Colloid
Interface Sci. - 1999. -V.218. - P.300-308.
15. Gregg S. J. and Sing K.S.W. Adsorption, Surface Area, and Porosity. New York:
Academic Press, 1982.
16. De Benedetto G.E., Malitesta C., and Zambonin C.G. Electroanalytical/X-ray
photoelectron spectroscopy investigation on glucose oxidase adsorbed on platinum
// J. Chem. Soc. Faraday Trans. - 1994. - V.90, N11. - P.1495-1499.
17. Kadlec O. and Dubinin M.M. Coments on the limits of applicability of the
mechanism of capillary condensation // J. Colloid Interface Sci. - 1969. - V.31, N4.
- P.479-489.
Z.V. Smelaya and Yu.G. Goltsov
Abstract
Introduction
Results and discussion
Template
Conclusions
Conclusions
References
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