Detection of ammonia in human breath using quartz crystal microbalance sensors with functionalized mesoporous SiO2 nanoparticle films

On-line Ammonia Sensor and Invisible Security Ink by Fluorescent Zwitterionic Spirocyclic Meisenheimer Complex

“…But for medical application, the sensor has to be sensitive enough to detect ammonia in the ppb range. Ammonia is a potential disease biomarker51 and recently there are reports to identify ammonia related diseases like renal insufficiency52, hepatic dysfunction53, Helicobacter pylori infection54, or halitosis55. Moreover, ammonia sensors can be useful in environmental gas analysis, automotive industry, chemical industry and sewer treatment.…”

The Measurement of Ammonia in Human Breath and its Potential in Clinical Diagnostics

“…Breath analytics is based on the hypothesis that the concentrations of VOCs in blood can be related to their concentration in breath as humidified VOCs (Ogimoto et al, 2015). There are limitations to this hypothesis as VOCs can be produced in the oral cavity, airways, by bacteria in the gut, or be emitted from mucus, saliva, and aerosols in the respiratory tract (Lourenco and Turner, 2014).…”

“…However, most of the developed instrumental techniques are typically complex, expensive and not suitable for diagnostic application. In addition, a number of the methods contribute to pre-analytical errors due to issues such as sample transportation and handling.While a number of sensor-based approaches have been developed including quartz crystal microbalance (Becker and Cooper, 2011;Ishida et al, 2008;Ogimoto et al, 2015), chemical and optical sensors, many of these have had challenges in terms of detection limits, or operation in real humidified breath samples, which has made them unsuitable for physiological application. However, some have now demonstrated effective application in human clinical studies (Hibbard et al, 2013).…”

Modification of nanocrystalline TiO2 coatings with molecularly imprinted TiO2 for uric acid recognition

“…The quartz crystal microbalance (QCM) is a simple, portable, cost‐effective, high‐resolution mass‐sensing instrument, which has been favorably adopted for analytical application because of its extreme sensitivity to the nanogram level of mass change loaded onto surface of the QCM resonator . As a mass sensor, QCM has been widely used in biochemistry, environment, food, life science, and clinical analysis because the instrument provides a label‐less method for the direct study of biospecific interaction process . Still, the QCM response lacks selectivity because of the nature of mass sensing, which will limit its application.…”