Článek si všímá posledních prezentovaných prací s problematikou elektrochemické detekce insulinu a předkládá kritický pohled na výzkum a vývoj jeho elektrochemických neenzymových senzorů. Monitoruje vliv experimentálních podmínek na insulinový oxidační signál a zamýšlí se nad katalytickými efekty nanočástic či nanokompozitů deponovaných na površích elektrochemického snímače.
The article notes the latest presented work on the electrochemical detection of insulin and presents a critical view of the research and development of its electrochemical non-enzymatic sensors. It monitors the effect of experimental conditions on the insulin oxidation signal and considers the catalytic effects of nanoparticles or nanocomposites deposited on the surfaces of the electrochemical sensor.
In this paper, heavy metal biosensor based on immobilization of metallothionein (MT) to the surface of carbon paste electrode (CPE) via anti-MT-antibodies is reported. First, the evaluation of MT electroactivity was done. The attention was focused on the capturing of MT to the CPE surface. Antibodies incorporated and mixed into carbon paste were stable; even after two weeks the observed changes in signal height were lower than 5%. Further, the interaction of MT with polyclonal chicken antibodies incorporated in carbon paste electrode was determined by square-wave voltammetry. In the voltammogram, two signals--labelled as cys(MT) and W(a)--were observed. The cys(MT) corresponded to -SH moieties of MT and W(a) corresponded to tryptophan residues of chicken antibodies. Time of interaction (300 s) and MT concentration (125 μg/ml) were optimized to suggest a silver(I) ions biosensor. Biosensor (CPE modified with anti-MT antibody) prepared under the optimized conditions was then used for silver(I) ions detection. The detection limit (3 S/N) for silver(I) ions was estimated as 0.5 nM. The proposed biosensor was tested by detection spiking of silver(I) ions in various water samples (from very pure distilled water to rainwater). Recoveries varied from 74 to 104%.
- MeSH
- Equipment Failure Analysis MeSH
- Biosensing Techniques instrumentation MeSH
- Equipment Design MeSH
- Electrodes MeSH
- Immunoassay instrumentation MeSH
- Conductometry instrumentation MeSH
- Metallothionein chemistry immunology MeSH
- Surface Properties MeSH
- Antibodies chemistry immunology MeSH
- Silver analysis immunology MeSH
- Carbon chemistry MeSH
- Protein Binding MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
Low-molecular mass proteins rich in cysteines called metallothioneins (MT) can be considered as markers for the pollution of the environment by metals. Here, we report on suggestion for an automated procedure for the isolation of MT followed by voltammetric analysis. Primarily, we optimized the automated detection of MT using an electrochemical analyser. It was found that the most sensitive and repeatable analyses are obtained at a temperature of 4 °C for the supporting electrolyte. Further, we optimized experimental conditions for the isolation of MT by using antibody-linked paramagnetic microparticles. Under the optimal conditions (4 h long interaction between the microparticles and MT), the microparticles were tested on isolation of various amounts of MT. The lowest isolated amount of MT by antibody-linked paramagnetic microparticles was 5 μg ml(-1) of MT (50 ng). The automated procedure of MT isolation was further tested on isolation of MT from guppy fish (Poecilia reticulata) treated with silver(i) ions (50 μM AgNO(3)). The whole process lasted less than five hours and was fully automated. We attempted to correlate these results with the standard method for MT isolation. The correlation coefficient is 0.9901, which confirms that results are in good agreement. Moreover, the concentration of silver ions in tissues of fish treated with Ag(i) ions was determined by high performance liquid chromatography with electrochemical detection.
- MeSH
- Water Pollutants, Chemical toxicity MeSH
- Magnetics MeSH
- Metallothionein chemistry isolation & purification metabolism MeSH
- Environmental Monitoring methods MeSH
- Poecilia metabolism MeSH
- Animals MeSH
- Check Tag
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
