Breath sensors can revolutionize medical diagnostics by on-demand detection and monitoring of health parameters in a noninvasive personalized fashion. Despite extensive research for more than two decades, however, only few breath have been translated into clinical practice. Actually, most never even left the scientific laboratories. Here, we describe key challenges that currently impede realization highlight strategies to overcome them. Specifically, start with marker selection (with...

Methanol poisoning causes blindness, organ failure or even death when recognized too late. Currently, there is no methanol detector for quick diagnosis by breath analysis screening of laced beverages. Typically, chemical sensors cannot distinguish from the much higher ethanol background. Here, we present an inexpensive and handheld sensor highly selective detection. It consists a separation column (Tenax) separating interferants like ethanol, acetone hydrogen, as in gas chromatography,...

Formaldehyde (FA) is a potential breath marker for lung cancer and tracer indoor air quality monitoring. Its typical concentrations are below 100 ppb posing sensitivity selectivity challenge to current portable sensor systems. Here, we present highly sensitive, selective, compact electronic nose (E-nose) real-time quantification of FA at realistic conditions. This E-nose consists four nanostructured porous Pt-, Si-, Pd-, Ti-doped SnO2 sensing films directly deposited onto silicon wafer-based...

Exhaled isoprene could enable non-invasive monitoring of cholesterol-lowering therapies. Here, we report an isoprene-selective sensor at high relative humidity (RH) for the first time (to our knowledge). It is made nanostructured, chemo-resistive Ti-doped ZnO particles (10-20 nm crystal size) produced by flame spray pyrolysis (FSP) and directly deposited in one step onto compact substrates forming highly porous films. The constituent consist stable solid solutions Ti levels up to 10 mol%...

Obesity is a global health threat on the rise, and its prevalence continues to grow. Yet suitable biomedical sensors monitor body fat burn rates in situ, guide physical activity or dietary interventions toward efficient weight loss, are missing. Here, we introduce compact inexpensive breath acetone sensor based Si-doped WO3 nanoparticles that can accurately follow real time. We tested this 20 volunteers during exercise rest measured their individual concentrations good agreement with...

Earthquakes are lethal natural disasters frequently burying people alive under collapsed buildings. Tracking entrapped humans from their unique volatile chemical signature with hand-held devices would accelerate urban search and rescue (USaR) efforts. Here, a pilot study is presented compact orthogonal sensor arrays to detect the breath- skin-emitted metabolic tracers acetone, ammonia, isoprene, CO2, relative humidity (RH), all together serving as sign of life. It consists three...

Isoprene is a versatile breath marker for noninvasive monitoring of high blood cholesterol levels as well influenza, end-stage renal disease, muscle activity, lung cancer, and liver disease with advanced fibrosis. Its selective detection in complex human by portable devices (e.g., metal-oxide gas sensors), however, still challenging. Here, we present new filter concept based on activated alumina powder enabling fast highly isoprene at the ppb level humidity. The contains surface area...

Formaldehyde is a carcinogenic indoor air pollutant emitted from wood-based furniture, building materials, paints and textiles. Yet, no low-cost sensor exists for on-site monitoring to fulfill stringent current upcoming (e.g., 8 parts-per-billion by volume, ppb, in France 2023) exposure guidelines. Here, we present an inexpensive handheld formaldehyde detector with proven performance real air. Selectivity achieved compact packed bed column of nanoporous polymer sorbent that separates...

Acetone is a toxic air pollutant and key breath marker for non-invasively monitoring fat metabolism. Its routine detection in realistic gas mixtures (i.e., human indoor air), however, challenging, as low-cost acetone sensors suffer from insufficient selectivity. Here, compact detector sensing introduced, having unprecedented selectivity (>250) over the most challenging interferants (e.g., alcohols, aldehydes, aromatics, isoprene, ammonia, H2, CO). That way, quantified with fast response (<1...

Combustion aerosol technology has distinct advantages for the assembly of chemoresistive gas sensors compared to their traditional wet chemistry synthesis. These are traced combustion's steep temperature gradients and high particle concentrations during sensing formation film deposition. This gives direct access a plethora material compositions (e.g. metastable phases, solid solutions, mixed oxides) fractal-like porous but rigid structures that can lead unique sensor selectivity, sensitivity...

Humanity endeavors to resume crewed missions the Moon and prepares for exploration of Mars.These will require sustained human presence in space longer periods than ever before.Space exposes astronauts demanding conditions, including microgravity, radiation, rapid light-dark cycles, hazardous chemicals.Gas sensors be pivotal preserving astronaut health by providing critical data (e.g., through breath analysis) space-resolved environmental information.Here, we explore recent progress gas meet...

Ketogenic diet (KD; high fat, low carb) is a standard treatment for obesity, neurological diseases (e.g., refractory epilepsy) and promising method athletes to improve their endurance performance. Therein, the level of ketosis must be regulated tightly ensure an effective therapy. Here, we introduce compact inexpensive breath sensor monitor online non-invasively. The consists Si-doped WO3 nanoparticles that detect acetone selectively with non-linear response characteristics in relevant range...

Fast and selective detection of NH3 at parts-per-billion (ppb) concentrations with inexpensive low-power sensors represents a long-standing challenge. Here, room temperature, solid-state sensor is presented consisting nanostructured porous (78%) CuBr films. These are prepared by flame-aerosol deposition CuO onto substrates followed dry reduction bromination. Each step monitored in situ through the film resistance affording excellent process control. Such films feature an order magnitude...

Routine detection of health parameters is desirable to recognize the early onset metabolic diseases (e.g., diabetes mellitus) and personalize their treatment. Promising are non-invasive, affordable portable technologies, such as breath sensors. Yet, selective monitoring markers acetone for lipolysis) with sensors track changes that can reveal disease-related abnormalities remains challenging. Here, subtle during fasting, exercise glucose ingestion tracked in two model situations: Patients...

Breath analysis has the potential to detect and monitor diseases as well reduce corresponding medical costs while improving quality of a patient's life. Herein, portable prototype, consisting commercial breath sampler modified work platform for solid-state gas sensors was developed. The sensor is placed close mouth (<10 cm) minimizes mouth-to-sensor path avoid contamination dilution target marker. Additionally with an appropriate cooling concept, even high operating temperatures (e.g. 350...

Ethanol is a major confounder in gas sensing because of its omnipresence indoor air and breath from disinfectants or alcoholic beverages. In fact, most modern sensors (e.g., graphene, carbon nanotubes, metal oxides) are sensitive to ethanol. This challenging ethanol often present at higher concentrations than target analytes. Here, simple modular packed bed filter presented that selectively continuously removes (and other alcohols like 1-butanol, isopropanol, methanol) over critical acetone,...

The coronavirus disease 2019 (COVID-19) pandemic has increased dramatically the demand for hand sanitizers. A major concern is methanol adulteration that caused more than 700 fatalities in Iran and U.S.A. (since February 2020). In response, U.S. Food Drug Administration restricted content sanitizers to 0.063 vol% blacklisted 212 products (as of November 20, Here, we present a low-cost, handheld, smartphone-assisted device detects selectively between 0.01 100 within two minutes. It features...