Patent ID: 7857963
Filing Date: 2010-12-28
Classification: G01N

Abstract:
1. A method of detecting or quantifying a target substance contained in a sample solution with an apparatus for electrochemical measurements comprising a reference electrode, an auxiliary electrode and an electrode plate for electrochemical measurements, or a counter electrode and an electrode plate for electrochemical measurements, wherein: the sample solution contains an electronic mediator, the electrode plate for electrochemical measurements consists of a first electrode plate or a second electrode plate, the first electrode plate comprising a substrate made of an insulator, an upper layer made of an insulator provided on an upper face of the substrate, a lower layer made of an insulator provided on a lower face of the substrate, a first electrode body sandwiched between the upper face of the substrate and the upper layer, and a second electrode body sandwiched between the lower face of the substrate and the lower layer, wherein: the substrate has a plurality of substrate through-holes; the upper layer has a plurality of upper layer through-holes; the first electrode body has a plurality of first electrodes composed of a portion exposed from an upper face of the upper layer via the upper layer through-hole; the second electrode body has a plurality of second electrodes composed of a portion exposed from the upper face of the upper layer via the upper layer through-hole and the substrate through-hole, and wherein: on a plane view, any of the plurality of substrate through-holes does not overlap with the first electrodes; four or more second electrodes having substantially the same area are disposed around the each first electrode, with an even distance between centers of the first electrode and each of the second electrodes; and two first electrodes having substantially the same area are disposed around the each second electrode, with an even distance between centers of the second electrode and each of the first electrodes, further wherein: the area of the each first electrode and total area of the second electrodes therearound are substantially the same, the second electrode plate comprising a substrate made of an insulator, an upper layer made of an insulator provided on an upper face of the substrate, a lower layer made of an insulator provided on a lower face of the substrate, a first electrode body sandwiched between the upper face of the substrate and the upper layer, and a second electrode body sandwiched between the lower face of the substrate and the lower layer, wherein: the substrate has a plurality of substrate through-holes extending through from the upper face to the lower face of the substrate; the upper layer has a plurality of upper layer through-holes extending through from the upper face to the lower face of the upper layer; the first electrode body has a plurality of first electrodes composed of a portion exposed from an upper face of the upper layer via the upper layer through-hole; and the second electrode body has a plurality of second electrodes composed of a portion exposed from the upper face of the upper layer via the upper layer through-hole and the substrate through-hole, and wherein: on a plane view, any of the plurality of substrate through-holes does not overlap with the first electrodes; four or more first electrodes having substantially the same area are disposed around the each second electrode, with an even distance between centers of the second electrode and each of the first electrodes; two second electrodes having substantially the same area are disposed around the each first electrode, with an even distance between centers of the first electrode and each of the second electrodes; and the area of the each second electrode and total area of the first electrodes therearound are substantially the same, said method comprising the steps of: bringing the reference electrode, the auxiliary electrode and the electrode plate for electrochemical measurements, or the counter electrode and the electrode plate for electrochemical measurements into contact with the sample solution; sweeping a positive potential to either one of the first electrode body and the second electrode body, and applying a negative potential to the other one, or applying a positive potential to either one of the first electrode body and the second electrode body, and sweeping a negative potential to the other one, to measure the electric current that flows between the first electrode body and the second electrode body; and calculating the amount of the target substance or detecting the target substance on the basis of the electric current.