| Abstract: | An endoscopic tube-tip type urease sensor was developed for the purpose of on-site detection of Helicobacter pylori (H. pylori) using a pH-sensitive field effect transistor (pH-FET). The sensor is composed of an endoscopic-tube connected to a feed pump with a urea solution and a pH-FET attached to a sensor holder at the open end of the tube. The urease activity on the gastric wall can be measured by bringing the sensor into contact with the gastric wall just after replacing gastric juice with the urea solution. The presence of H. pylori causes a pH change in the urea solution inside the sensor holder in 20 seconds due to the strong urease activity of this bacterial species. After measurement, the sensor is detached from the wall, and washed with urea solution by turning on the urea pump. A measurement at one site is completed within 30 seconds. Repetition of the procedure makes multi-site measurements possible. In preliminary evaluations, it was found that clinical sensitivity and specificity were 89% and 86%, respectively, using standard bacteriological testing results as a reference. |
