Method for diagnosing Alzheimer's disease using biomaterial

A method for measuring a concentration of beta-amyloid in a sample, comprising:

• preparing magnetic particles on which primary capture antibodies specifically bound to beta-amyloid are adsorbed;
• decomposing a biomaterial including the beta-amyloid;
• binding the beta-amyloid to the primary capture antibodies;
• binding secondary capture antibodies labeled with a fluorescent material to the magnetic particles bound to the beta-amyloid to form a complex;
• disposing the complex over a channel pattern of a photo field effect transistor having a photocurrent that is changed according to an amount of incident light;
• and
• measuring the photocurrent changed by light excited from the complex to quantify the concentration of the beta-amyloid existing in the biomaterial,
• wherein the photo field effect transistor includes:
• a semiconductor substrate;
• an insulating layer disposed on the semiconductor substrate;
• the channel pattern, which is disposed on the insulating layer;
• first and second wiring electrodes disposed directly on an upper surface of the channel pattern, an upper surface of the insulating layer, and sidewalls of the channel pattern;
• and
• a light filter layer disposed on the upper surface of the channel pattern and sidewalls of the first and second wiring electrodes,
• wherein the channel pattern is defined by a side of the insulating layer and a side of the light filter layer, the first and second wiring electrodes defining sidewalls of the channel pattern,
• wherein disposing the complex comprises fixing the complex onto a surface of the light filter layer and over the channel pattern of the photo field effect transistor by a source of an external magnetic field located under the semiconductor substrate, and
• wherein the light filter layer passes through only a wavelength of light excited from the fluorescent material.