Portable and Hand-Held Ammonia Gas Sensor Enables Noninvasive Prediagnosis of <i>Helicobacter pylori</i> Infection

Abstract

Disease diagnosis of Helicobacter pylori (Hp) through human exhaled breath analysis has attracted considerable attention. However, conventional methods, such as carbon 13 ( 13 C) breath test and infrared spectrometers, are facing the challenge of achieving portability and reliability synchronously. Herein, we report a portable and hand-held Hp analyzer using a bimetallic PtRu@SnO 2 -based gas sensor for the prediagnosis of Hp infection, which is based on detecting ammonia (NH 3 ) as a potential biomarker in exhaled breath. Owing to the surface functionalization through highly catalytically active bimetallic PtRu nanoparticles (NPs) prepared by a photochemical reduction strategy, the PtRu@SnO 2 -based sensor exhibits high sensitivity and selectivity toward trace-level (200 ppb) NH 3 even at high-humidity surroundings (80% RH). Consequently, the designed portable and hand-held Hp analyzer makes the accurate determination of NH 3 at 800 ppb in exhaled breath. The tuning of energy band structure and electrical characteristics and the catalytic modulation of NH 3 oxidation by PtRu NPs are proposed to be the reasons behind the enhanced NH 3 gas-sensing performance, as confirmed by in situ analysis using an online MKS MultiGas 2030 FTIR gas analyzer. This work paves the way for the prediagnosis of Hp infection using a metal oxide gas sensor.