Organic Gas Sensor with an Improved Lifetime for Detecting Breath Ammonia in Hemodialysis Patients

Abstract

In this work, a TFB (poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-(4,4'-(N-(4-s-butylphenyl)diphenylamine)]) sensor with a cylindrical nanopore structure exhibits a high sensitivity to ammonia in ppb-regime. The lifetime and sensitivity of the TFB sensor were studied and compared to those of P3HT (poly(3-hexylthiophene)), NPB (N,N'-di(1-naphthyl)-N,N'-diphenyl-(1,1'-biphenyl)-4,4'-diamine), and TAPC (4,4'-cyclohexylidenebis[N,N-bis(4-methylphenyl) benzenamine]) sensors with the same cylindrical nanopore structures. The TFB sensor outstands the others in sensitivity and lifetime and it shows a sensing response (current variation ratio) of 13% to 100 ppb ammonia after 64 days of storage in air. A repeated sensing periods testing and a long-term measurement have also been demonstrated for the test of robustness. The performance of the TFB sensor is stable in both tests, which reveals that the TFB sensor can be utilized in our targeting clinical trials. In the last part of this work, we study the change of ammonia concentration in the breath of hemodialysis (HD) patients before and after dialysis. An obvious drop of breath ammonia concentration can be observed after dialysis. The reduction of breath ammonia is also correlated with the reduction of blood urea nitrogen (BUN). A correlation coefficient of 0.82 is achieved. The result implies that TFB sensor may be used as a real-time and low cost breath ammonia sensor for the daily tracking of hemodialysis patients.

Construction of 1D/2D α -Fe 2 O 3 /SnO 2 Hybrid Nanoarrays for Sub-ppm Acetone Detection

“…Encouragingly, a few of them have been regarded as biomarkers to diagnose diseases (Table S1). For example, formaldehyde (lung cancer) [4], toluene (lung cancer) [5], ammonia (hemodialysis) [6], H 2 S (halitosis) [7], isoprene (heart disease) [8], benzene (smoker) [9], and pentane (acute asthma) [10] at few dozens to few thousands of ppb are known as biomarkers for patients. Researchers have also found that exhaled acetone can intuitively correlate with type-1 diabetes, which may exceed 1.8 ppm (only 0.3-0.9 ppm for healthy people) [1,11].…”

A Smart Rig for Calibration of Gas Sensor Nodes

“…Some types of these sensors are used for monitoring and controlling the combustion processes [1][2][3]. Oxygen and other types of sensors are used in medical applications, for example, for analyzing human breath [4][5][6]. Gas sensors may also be used in electronic olfaction schemes for odor detection and identification [7][8][9][10].…”

50.2: Invited Paper: Improving lifetime and output current of organic‐based gas sensor for applications in breath detection

“…[1][2][3] In this context, many organic gas sensors including our prior works have been reported for BA detection. 4,5 However, one of the major challenges for its integration with affordable household POC application is to achieve stable performance for accuracy and high operational current at low voltage for low-cost read-out circuitry. In recent years, organic semiconductor devices were demonstrated to exhibit good sensitivity to ammonia in parts-per-billion (ppb) concentrations.…”