The investigators will develop a urinary multimarker sensor, able to measure trace amounts of biomarkers from naturally voided urine.
1. Urine specimen collection. This study was approved by the Institutional Review Board of the Asan Medical Center (Seoul, Republic of Korea) and informed consent will be obtained from all subjects. Biomarkers diffused passively from prostate tissue to the urethra and will be collected from naturally voided urine. Urine will be collected in a sterilized specimen cup containing 10 vol% RNA stabilizer and 1vol% antibiotics and stored in a refrigerator for less than a week before shipping the sample to the laboratory
2. To measure the electrical signals from the four different biomarkers in the urine, the four sensing channels in the extended gate of an field-effect transistor biosensor will be conjugated to antibodies, thus capturing different biomarkers.
3. Without any pretreatment, urine will be added directly to the four different sensing channels. After 20 min of reaction time in the four channels, the bottom gate voltage shifts will be measured at the reference current (1 nA). Each urine sample will generate four independent sensing signals from the corresponding biomarkers. The set of sensing signals collected for each patient will be then analyzed.
