There is provided a cholesterol sensor with high-accuracy and excellent response, whose object to be measured is whole blood, where plasma with which is obtained by filtering out hemocytes therein filtered in blood can rapidly reach an electrode system. In a biosensor where plasma with which is obtained by filtering out hemocytes therein filtered with by 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.
1. A biosensor comprising:
An an insulating base plate;
an electrode system having a working electrode and a counter electrode which are provided on said base plate;
a reagent including at least oxidoreductase and an electron mediator;
a sample solution supply pathway which includes said electrode system and said reagent and has an air aperture on the termination side thereof;
a sample supply part; and
a filter which is disposed between said sample solution supply pathway and said sample supply part and which filters out hemocytes, where plasma with hemocytes therein filtered with said filter is sucked into said sample solution supply pathway due to capillarity ,
characterized by further comprising:
a first pressing part for holding a primary side portion of said filter from the bottom;
a second pressing port part for holding a secondary side portion of said filter from the top and the bottom;
a third pressing part for holding the central portion of said filter from the top; and
a void for surrounding said filter between said second pressing part and third pressing part.
2. The biosensor in accordance with claim 1 , characterized in that said primary side portion of said filter is exposed outside at the upper face of the biosensor.
3. The biosensor in accordance with claim 1 , characterized in that said secondary side portion of said filter and said working electrode are not in contact with each other.
4. The biosensor in accordance with claim 2 , characterized in that said secondary side portion of said filter and said working electrode are not in contact with each other.