A transcutaneous hydrogen sensor: From design to application

A transcutaneous hydrogen gas sensor of unprecedented sensitivity was fabricated and applied as a diagnostic tool for determining lactose intolerance due to lactase deficiency. The sensor, based on the use of highly-ordered titania nanotube arrays made by anodization of a 250 mu m thick titanium foil, shows a change in electrical resistance of 8.7 orders of magnitude when cycled between air and nitrogen containing 1000 ppm of hydrogen. The sensor is completely reversible with a response time of about 30 seconds. Lactose intolerance tests were conducted at the Pediatric Gastroenterology Clinic of the Penn State Children's Hospital, where the transcutaneous hydrogen gas concentration from lactose intolerant patients was monitored and compared to hydrogen levels in exhaled breath. Results indicate a direct correlation between the transcutaneous and exhaled-breath hydrogen gas concentrations.