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6 AZ9RBAYCAN KIMYA JURNALI № 2 2017
UDC 544.344; 577.1.08
PHYSICO-CHEMICAL PROPERTIES OF BIOMIMETIC SENSOR
TPhPFe(m)OH/AhO3/Si
N.N.Malikova, N.I.Ali-zadeh, T.M.Nagiev
M.Nagiev Institute of Catalysis and Inorganic Chemistry, NAS of Azerbaijan
[email protected] Received 01.12.2016
Researched and developed biomimetic sensor based on biomimetic smart material and the semiconductor (Si). Prepared biomimetic sensor compared with their biological counterparts have a number of technological advantages - availability, easeness of use and long working life. Its high activity sensitive and to determine steadiness permit the concentrations in aqueous solution of H2O2 to 10-6 mas.% and ethyl alcohol to 10-4 mas.%.
Keywords: biomimetic sensor, electrode, catalase activity, peroxidase activity.
Biosensors attract the attention of researchers and practitioners because of their low cost, small sizes, allow to continuously monitor biochemical processes in biotechnology, to determine the quality of food products, their composition, the content of toxins, antibiotics, and to perform environmental monitoring.
Having successful works in the field of simulation of catalysis it is possible to prepare biomimetic analogues of the corresponding enzymes by using sensors which will provide an opportunity to get rid of many of the disadvantages (high cost, high sensitivity to the effects of the external environment, multistage determine short-term operation, etc.) of known sensors.
In works [1, 2] the studies in this direction carried out are described. It has been shown that replacement of the active part (operation member) for chemical analogues (biomimetics) allowed to explore design and physicochemical features biomimetic sensors of catalase and pe-roxidase types.
Nowadays, semiconductor biosensors characterized with good reproducibility, high sensitivity, availability and cheapness, are widely used.
Semiconductors can be seen in the "heart" of microprocessor chips, and in the transistor. Any device connected to the computer or use a radio frequency is directly related to the use of semiconductors.
Today, the majority of semiconductor chips and transistors are made on the basis of silicon.
For this purpose iron porphyrin biomimetic electrode based on silicon (Si) was examined. Silicon (Si) is one of the basic materials used for the creation of bio- and chemical sensors, which is due to manufacturability and low cost. Tetraphenylporphyrin iron adsorbed on alumina (TPhPFe(III)OH/Al2O3) was applied on silicon (Si) substrate by gluing.
Investigations were carried out in an electrochemical cell (Figure 1).
-v-
Adhesive
...... e
TPhPFe(lll)AI?Q:1
Fig. 1. Electrochemical cell.
Catalase and peroxidase activity of biomimetic sensor was determined by potentio-metric method. Experimental set-up to carry out these studies consisted of a part of the electrode, cell and universal voltmeter V7-21A and "Sa-na"-MV-Meter SL 901. The electrode part of the mounting consists of comparison electrode
Referens
(Ag/AgCl/Cl-) and prepared by us biomimetic electrode. The background solution served as bidistillated water.
Biomimetic sensor was prepared by gluing a smart material on Si-substrate (electrode transducer). The adhesive material used as a silver paste.
To study the physical and chemical characteristics of biomimetic sensors prepared by us, as a working smart material used iron tetra-phenylporphyrin.
Working material - biomimetics must be in direct contact with the transducer. Therefore, to create this link, we have used conductive silver paste. It was found that silver paste is practically inert with respect to the aqueous solution of H2O2 and water-alcohol solution.
Figure 2 shows the variation of the e.m.f system depending on the time for Si-electrode without imitator. Studies have dis played that the Si-electrode (without imitator) does not decompose the low concentrations of H2O2.
AE, mV 1
0.4 0.3 0.2-1
0.1 -
0
20
40
60
t, s
80
Fig.2. Change of the e.m.f. system depending on the time for Si-electrode without imitator.
Results of potentiometric studies of TPhPFe(ni)OH/Al2O3 biomimetic electrode catalase activity are cited in Figure 3.
As seen in Figure 3 the electrode potential of the background solution makes up AE = (-0.231 mV) for concentration of H2O2 in aqueous solution of 1-10-4 mas. % and AE = (- 0.305 mV) for 1-10-6 mas.%.
Considering the curves (1, 2) in Figure 3 it can be seen that the iron porphyrin biomimetic sensor of catalase type exhibits high sensitivity to H2O2 [3, 4].
It can also seen from the figure that there is observed an abrupt leap of electrode potential within a few seconds when adding H2O2 (in both cases).
AE, mV ft
-0.33 -0.29 -0.25
Ethyl alcohol is one of the most important technical products and kinds of raw material. As we know a considerable amount of etha-nol produced from food raw materials is consumed for the preparation of alcoholic beverages, which requires a clear and precise control over the content of ethyl alcohol in these products. So it was interesting to explore catalase biomimetic sensor on the peroxidase activity.
For this purpose potentiometric studies were conducted to determine trace concentrations of ethanol in aqueous solution.
Figure 4 shows the experimental data obtained during the study of peroxidase activity of iron tetrafenilporphyrin containing biomimetic electrode, at concentration of H2O2 is equal to 0.1 mas.% and various concentrations of C2H5OH.
Studies have shown that at a constant concentration of H2O2 equal to 0.1 mas.% electrode potential background hydro-alcoholic solution is: for concentrations C2H5OH 0.5 mas.% AE = (-0.214 mV); C2H5OH 0.1 mas.% AE = (-0.212 mV); C2H5OH-10-4 mas.% AE = (-0.208 mV).
In addition, Figure 5 presents the experimental data obtained during the study of peroxidase activity of tetrafenilporphyrin biomimetic
8
N.N.MALIKOVA et al.
electrode for concentration 0.5 mas.% C2H5OH at various concentrations of H2O2. It was necessary to measure the electrochemical potential of the 0.5% - aqueous solution of ethyl alcohol while analyzing curves of Figure 5, to study the peroxidase reaction.
Fig.4. Change of the e.m.f. system depending on the time of when CH2o2 = 0.1 mas. % and various concentrations C2H5OH: 1 - bidistilled water and water-alcohol solution, 2 - CH2O2 = 0.1 mas.%, 3 - CH2O2 = 0.1 mas.% + 110-4 mas.% GftOH, 4 - CH2O2 = 0.1 mas.% + 0.1 mas.% C2H5OH, 5 C2H5OH.
NE, mV
CHo = 0.1 mas.% + 0.5 mas.%
As is seen from the Figure 5 the value of 0.5 % - aqueous solution of ethyl alcohol is completely identical with potentials of redistilled water (Figure 5, curve 1).
Thus, the water-alcohol solution remains nearly inert with respect to the biomimetic sensor and the concentration of H2O2 is ranged from 1-10-6 mas. % to 0.5 mas. % [5, 6].
Considering the curves (2-4) of Figure 5 we can see that biomimetic sensor of peroxidase type exhibits high sensitivity.
The electrode potential of carrier solution is: for H2O2 concentration of 0.5 mas.% ДЕ= (-0.191 mV); for H2O2 concentration of 1-10"4 mas. % ДЕ = (-0.2 mV); for H2O2 concentration of 0.1 mas. % ДЕ = (-0.1 mV), where the water-alcohol solution remained constant and was 0.5 mas.% in all cases.
Thus, in an electrochemical system under study the biomimetic sensor had a limit sensitivity: to the concentration of H2O2 equal to 10-6 mas.% and also allows detection of etha-nol in aqueous solution in an amount equal to 10-4 mas.%
References:
1. Nagiev T.M. Coherent Synchronized Oxidation by Hydrogen Peroxide. Amsterdam: Elsevier, 2007. 325 p.
2. Nagiev T.M. Biomimetic Based Application. Preface IX. Chapter 4. Croatia. INTECH. 2011. P. 105.
3. Malikova N.N., Ali-zadeh N.I., Nagiev T.M. Catalase-biomimetic sensor on base of electrochemical electrode TPhPFe(III)/Al2O3/Pb and TPhPFe(III)/Al2O3/Si // J. Chem. Chem. Eng. (USA). www.davidpublishing. com 2015. V. 9. No 1. January (Serial Number 86), P. 67-70.
4. Malikova N.N., Ali-zadeh N.I., Nagiev T.M. Cata-lase biomimetic sensor on base of silicon electrode TPhPFe3+/Al2O3/Si // 34th International Conference on Solution Chemistry 2015. 30th August-3rd September. Prague, Czech Republic. P 41.
5. Malikova N.N., Ali-zadeh N.I., Nagiev T.M. Per-oxidase-biomimetic sensor on base of silicon electrode - TPhPFe(III)/Al2O3/Si // ECCE10+ ECAB3+ EPIC5 2015. September 27th-October 1th. Nice, France. P.1039.
6. Malikova N.N., Ali-zadeh N.I., Nagiev T.M. Semiconductor biomimetic electrode - TPhPFe(III)/Al2O3/Si for catalase and peroxidase types // CHISA-2016. Prague Symposium on progress in chemical technology and biotechnology. 2016. Praque, Chech Republic 27-31 august. Serial Number: 0821. P 1.109.
TPhPFe(III)OH/Al2O3/Si BiOMiMETiK SENSORUN FiZiKl-KlMYOVi XASSOLORl
N.N.Malikova, N.teii-zada, T.M.Nagiyev
Smart biomimetik material va yarimkegirici (Si) asasinda biomimetik sensor tadqiq olunub va i§lanib hazirlanmi§dir. Hazirlanmi§ biomimetik sensor oz bioloji analoqlan ila muqayisada bir sira texnoloji ustunluklara malikdir: asan alda olunur, istifadasi sadadir va uzun muddat i§lama qabiliyyatina malikdir. Oz aktivliyi, hassasligi va davamligi ila H2O2-ni 10-6 kut.%-a qadar va ttil spirtinin qatiligini 10-4 kut.%-a qadar sulu mahlulda qatiliglarini tayin etmaya imkan verir.
Agar sozlar: biomimetik sensor, elektrod, katalaz aktivliyi, peroksidaz aktivliyi.
ФИЗИКО-ХИМИЧЕСКИЕ ОСОБЕННОСТИ БИОМИМЕТИЧЕСКОГО СЕНСОРА
TPhPFe(In)OH/AbO3/Si
Н.Н.Меликова, Н.И.Али-заде, Т.М.Нагиев
Исследован и разработан биомиметический сенсор на основе смарт-биомиметического материала и полупроводника (Si). Приготовленный биомиметический сенсор по сравнению с их биологическими аналогами имеет ряд технологических преимуществ - доступность, простоту использования и длительный срок работы. Своими высокими активностью, чувствительностью и устойчивостью позволяет в водном растворе определять концентрации Н2О2 до 10-6 мас.% и этилового спирта до 10-4 мас.%.
Ключевые слова: биомиметический сенсор, электрод, каталазная активность, пероксидазная активность.
