Microbial sensor works - Solutions - Huaqiang Electronic Network

inductance

According to the relationship between the microorganism and the test substance, there are two cases: one is the aerobic microorganism as the sensitive material, and when it interacts with the substance to be tested (intermediate organic matter), the respiratory activity of the cell is improved. Therefore, the respiratory activity can be measured to determine the substance to be tested, and the mechanism constitutes a respiratory-active microbial sensor. The working principle is shown in (a). The aerobic microorganism is immobilized on the diaphragm type oxygen electrode to form a microbial electrode.

The electrode is inserted into a sample solution containing an organic compound that can be assimilated, and the organic compound is diffused into the solid phase gel containing the microbial cells and assimilated by the microorganism, and the respiratory activity of the microbial cells is increased after the assimilation of the organic substance, and thus diffused The amount of oxygen to the oxygen probe is correspondingly reduced. The oxygen current value is lowered, whereby the concentration of the organic substance assimilated by the microorganism can be indirectly determined. Because of this, this type of microbial sensor is generally a current-type microbial sensor. The other is a oxy-oxygen microbial sensitizing material.

Molecular recognition can be carried out by measuring various electrode-sensitive metabolites produced by assimilating organic matter. This constitutes a metabolite-type microbial sensor. The working principle is shown in Figure 12-36(b). If a substance that is small in the assimilation product is a sensitive substance of the electrode, the electrode can be used as a signal conversion device, and together with the same basic microbial membrane, a microbial sensor is used to determine the concentration of the substance to be tested. For example, a "hydrogen-producing bacterium" capable of generating hydrogen is fixed in a polymer gel, and then it is mounted on a fuel cell type (the battery is sufficiently white to be an anode, and silver peroxide (Ag2O2) is a cathode.

The microbial electrode can be immersed in a lily-containing electrode on the anode of a phosphate buffer (pH 7.0, an electrode active material such as hydrogen, which is an oxidation reaction on the anode, which can be an electric current). The solution of the organic food can be diffused into the hydroquinone in the gel film, and then assimilated to generate hydrogen. The generated hydrogen diffuses to the anode in close contact with the gel. It is oxidized on the anode, so the measured current value is proportional to the amount of hydrogen diffused. It is also smaller than the sample solution. The concentration of the organic compound is proportional, so the concentration of the compound to be tested is converted into a current to be measured.