Rapid diagnostic test for Helicobacter pylori using endoscopic urease probe

为了利用pH敏感场效应晶体管(pH-FET)对幽门螺杆菌进行现场检测，研制了一种内窥镜管尖型尿素酶传感器。该传感器由内窥镜管和pH-FET组成，内窥镜管连接到装有尿素溶液的进料泵，pH-FET连接在管的开口端的传感器支架上。用尿素溶液代替胃液后，将传感器与胃壁接触，即可测量胃壁上的尿素酶活性。幽门螺杆菌的存在会导致传感器支架内尿素溶液的pH在20秒内发生变化，这是因为这种细菌具有很强的尿素酶活性。测量结束后，将传感器从壁上拆卸下来，打开尿素泵，用尿素溶液冲洗。一个站点的测量在30秒内完成。重复这一过程使多点测量成为可能。以标准细菌学检测结果为参照，其临床敏感性和特异性分别为92.3%和89.7%。

An endoscopic tube-tip type urease sensor was developed for the purpose of on-site detection of 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. It was found that clinical sensitivity and specificity were 92.3% and 89.7%, respectively, using standard bacteriological testing results as a reference.