Biomimetic Electrode Research Articles

Development of a Molecularly Imprinted Biomimetic Electrode

The technique of molecular imprinting produces artificial receptor sites in apolymer that can be used in a biomimetic sensor. This research extends previous studies ofa molecularly imprinted polymer (MIP) biomimetic sensor for the small drug theophylline.The presence of theophylline in the biomimetic sensor was monitored by analyzing thepeak currents from cyclic voltammetry experiments. The functional working range of theMIP modified electrode was 2 - 4 mM theophylline. The concentration of theophyllinethat resulted in the best signal was 3 mM. The MIP sensor showed no response to thestructurally related molecule caffeine, and therefore was selective to the target analytetheophylline. This research will provide the foundation for future studies that will result indurable biomimetic sensors that can offer a viable alternative to current sensors.

Kinetics of the electron transfer reaction of Cytochrome c 552 adsorbed on biomimetic electrode studied by time-resolved surface-enhanced resonance Raman spectroscopy and electrochemistry

Cytochrome c (552) (Cyt-c (552)) and its redox partner ba ( 3 )-oxidase from Thermus thermophilus possess structural differences compared with Horse heart cytochrome c (cyt-c)/cytochrome c oxidase (CcO) system, where the recognition between partners and the electron transfer (ET) process is initiated via electrostatic interactions. We demonstrated in a previous study by surface-enhanced resonance Raman (SERR) spectroscopy that roughened silver electrodes coated with uncharged mixed self-assembled monolayers HS-(CH(2))( n )-CH(3)/HS-(CH(2))( n + 1)-OH 50/50, n = 5, 10 or 15, was a good model to mimic the Cyt-c (552) redox partner. All the adsorbed molecules are well oriented on such biomimetic electrodes and transfer one electron during the redox process. The present work focuses on the kinetic part of the heterogeneous ET process of Cyt-c (552) adsorbed onto electrodes coated with such mixed SAMs of different alkyl chain length. For that purpose, two complementary methods were combined. Firstly cyclic voltammetry shows that the ET between the adsorbed Cyt-c (552) and the biomimetic electrode is direct and reversible. Furthermore, it allows the estimation of both the density surface coverage of adsorbed Cyt-c (552) and the kinetic constants values. Secondly, time-resolved SERR (TR-SERR) spectroscopy showed that the ET process occurs without conformational change of the Cyt-c (552) heme group and allows the determination of kinetic constants. Results show that the kinetic constant values obtained by TR-SERR spectroscopy could be compared to those obtained from cyclic voltammetry. They are estimated at 200, 150 and 40 s(-1) for the ET of Cyt-c (552) adsorbed onto electrodes coated with mixed SAMs HS-(CH(2))( n )-CH(3)/HS-(CH(2))( n + 1)-OH 50/50, n = 5, 10 or 15, respectively.

Peptide derivatised poly(pyrrole)s — Towards a biomimetic electrode modelling the zinc containing redox enzyme alcohol dehydrogenase

Peptide derivatised poly(pyrrole)s — Towards a biomimetic electrode modelling the zinc containing redox enzyme alcohol dehydrogenase

Use of a copper-phthalocyanine membrane electrode for rapid preliminary detection of polycyclic mutagens

Preliminary screening of polycyclic mutagens is achieved within 20 min by using a biomimetic electrode composed of an oxygen electrode and a copper-phthalocyanine membrane. When benzo[α]pyrene (0.05 mM) was added to the buffer solution in the presence of 0.98 M hydrogen peroxide, the current of the phthalocyanine electrode decreased. A linear relationship was obtained between the current decrease and the benzo[α]pyrene concentration over the range 0.19–0.60 mM. The minimum measurable concentration for benzo[α]pyrene was 0.01 mM. Such responses were not obtained for other organic compounds such as alcohol, ether, n-hexane and cyclohexane. The copper-phthalocyanine membrane electrode has selectively detected polycyclic mutagens such as amino acid pyrolysis products. The current decrease was 1.18–1.46 μA when 0.05 mM amino acid pyrolysis products were employed.

バイオミメティック膜電極の新しい応用

Marked progress has been made in the development of membrane electrode in recent years. Several sensors based on inorganic, organic and bio-membrane electrode are available commercially and used in many fields. Various ion selective electrodes and biosensors have been developed for chemical analysis. In this paper, the biomimetic electrodes imitating biofunctions are described. There are three types of biomimetic membrane electrodes imitating the electron transfer system, photosynthesis system and nervous system.The biomimetic membrane electrodes are applied to analysis, bioelectronic devices and energy conversion. The present author have developed the biomimetic electrode using copper-phthalocyanine. The sensor composed of oxygen electrode and copper-phthalocyanine membrane was applied to preliminaly screening of mutagens. The biomimetic electrode was also used for the detection of microorganisms. Cell number determination and classification were carried out with 4, 4'-bipyridine-modified graphite electrode by using cyclic voltammetry.Thus, the biomimetic membrane electrode is promissing for detecting the materials which are not determined by ion selective electrodes and biosensors. They will also be employed for biochips and energy conversion.