Matsushita Electric Industrial Co., Ltd.

Miwa Hasegawa

Tomohiro Yamamoto

Shin Ikeda

Shiro Nankai

Motokazu Watanabe

Toshihiko Yoshioka

Takahiro Nakaminami

A biosensor comprising: an electrically insulating base plate; an electrode system comprising a working electrode and a counter electrode formed on the base plate; a cover member which is joined to the base plate to form a sample solution supply pathway for supplying a sample solution to the electrode system between the cover member and the base plate; and a reagent system comprising at least an oxidoreductase and an electron mediator disposed in the sample solution supply pathway, wherein the electron mediator is provided on the base plate and the oxidoreductase is provided on the cover member such that the electron mediator and the oxidoreductase are not in contact with each other.

Biosensor

There is provided a cholesterol sensor with high-accuracy and excellent response, whose object to be measured is whole blood, where plasmawithwhich is obtained by filtering outhemocytestherein filteredin bloodcan rapidly reach an electrode system. In a biosensor where plasmawithwhich is obtained by filtering outhemocytestherein filtered withbya filter is sucked into a sample solution supply pathway due to capillarity, there are formed: a first pressing part for holding a primary side portion of the filter from the bottom; a second pressing part for holding a secondary side portion of the filter from the top and the bottom; a third pressing part for holding the central portion of the filter from the top; and a void for surrounding the filter between the second pressing part and third pressing part.

To provide an improved biosensor which allows easy addition of whole blood to the sensor and rapid supply of the added whole blood to a filter even in the case of collecting blood by fingertip centesis for measurement, a second air aperture is provided in a sample solution supply pathway including an electrode system and a reaction layer and communicating with a first air aperture on the terminal end side.

A biosensor including an insulating base plate, an electrode system, a cover for covering the insulating base plate, at least one reaction layer, a sample solution supply pathway communicating with an air aperture at a terminal end side, a sample solution supply part and a filter provided between the sample solution supply pathway and the sample solution supply part to filter hemocytes, an end face and a top face of a primary portion of the filter are exposed and the sample solution supply part is provided adjacently to the primary side portion so as to provide an improved biosensor which allows easy addition of whole blood to the sensor and rapid supply of the added whole blood to a filter even in the case of collecting blood by fingertip centesis for measurement.

A sensor including an insulating base plate; an electrode system, provided on the base plate, having a measuring electrode and a counter electrode; a reaction layer including at least an oxidoreductase and an electron mediator; a sample solution supply pathway including the electrode system and the reaction layer; and a sample supply unit, wherein the sensor is so structured that, between the sample supply unit and the sample solution supply pathway, there is provided a filter having a function to filter out hemocytes and having a cross-sectional area larger than an opening of the sample solution supply pathway, and that plasma of a blood with hemocytes thereof having been filtered out is sucked into the inside of the sample solution supply pathway owing to capillary phenomena.

Disclosed is a highly responsive biosensor comprising a cholesterol-oxidizing enzyme and cholesterol esterase. The biosensor comprises: an electrically insulating base plate; an electrode system including a working electrode and a counter electrode formed on the base plate; a cover member joined with the base plate to define a sample supply pathway through which a sample solution is introduced from a sample supply port to the electrode system, the sample supply pathway being formed between the cover member and the base plate; and a reagent layer formed in the sample supply pathway, wherein the reagent layer contains a cholesterol-oxidizing enzyme, cholesterol esterase, an electron mediator, and a buffer having a buffering capacity in an acidic pH range.

Biosensor and method of substrate quantification

The present invention provides a biosensor that enables highly-accurate measurement of a sample solution including a solid component like hemocytes and has a little variation in response. The biosensor includes: an insulating base plate, an electrode system having at least a working electrode and a counter electrode provided on the base plate, a cover member that is combined with the base plate to define a sample solution supply pathway for leading a sample solution from a sample supply unit to the electrode system, a reaction reagent system including at least an oxidation-reduction enzyme and an electron mediator, and a filter disposed between the electrode system and the sample supply unit in the sample solution supply pathway. The biosensor has a space that encircles surface of the filter in an area from one end of the filter close to the sample supply unit to the other end of the filter close to the electrode system. This arrangement effectively prevents the solid component like hemocytes from flowing into the electrode system without being filtered out by the filter.

A biosensor includes: an insulating base plate; an electrode system which is provided on the base plate and has a measurement electrode and a counter electrode; a reaction layer including at least oxidoreductase and an electron mediator; a sample solution supply pathway which includes the electrode system and the reaction layer and has an air aperture on the termination side thereof; a sample supply portion; and a filter which is disposed between the sample solution supply pathway and the sample supply portion and filters hemocytes, where plasma with the hemocytes therein filtered with the filter is sucked into the sample solution supply pathway due to capillarity, the central part of a secondary side portion of the filter is protruded into the sample solution supply pathway more than both the right and left ends thereof.

There is provided a cholesterol sensor with high-accuracy and excellent response, whose object to be measured is whole blood, where plasma with hemocytes therein filtered can rapidly reach an electrode system. In a biosensor where plasma with hemocytes therein filtered with a filter is sucked into a sample solution supply pathway due to capillarity, there are formed: a first pressing part for holding a primary side portion of the filter from the bottom; a second pressing part for holding a secondary side portion of the filter from the top and the bottom; a third pressing part for holding the central portion of the filter from the top; and a void for surrounding the filter between the second pressing part and third pressing part.

The present invention provides a biosensor that has a reaction reagent system easily dissolved even in a sample solution containing a high concentration of a substrate and ensures rapid and highly accurate measurement. The method of forming a target reaction layer according to the present invention dissolves a material constituting the target reaction layer in a solvent of a sublimable substance to prepare a solution, applies the solution in a desired area to form the target reaction layer, freezes the applied solution, and sublimates the solvent included in a solid matter of the frozen solution under reduced pressure for removal. The resultant reaction layer has a large surface area and is easily dissolved in the sample solution to enable rapid measurement.

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Hyogo, Japan

Miwa Hasegawa