Breath analysis has the potential for early stage detection and monitoring of illnesses to drastically reduce the corresponding medical diagnostic costs and improve the quality of life of patients suffering from chronic illnesses. In particular, the detection of acetone in the human breath is promising for non-invasive diagnosis and painless monitoring of diabetes (no finger pricking). Here, a portable acetone sensor consisting of flame-deposited and in situ annealed, Si-doped epsilon-WO 3 nanostructured films was developed. The chamber volume was miniaturized while reaction-limited and transport-limited gas flow rates were identified and sensing temperatures were optimized resulting in a low detection limit of acetone (~20 ppb) with short response (10-15 s) and recovery times (35-70 s). Furthermore, the sensor signal (response) was robust against variations of the exhaled breath flow rate facilitating application of these sensors at realistic relative humidities (80-90%) as in the human breath. The acetone content in the breath of test persons was monitored continuously and compared to that of state-of-the-art proton transfer reaction mass spectrometry (PTR-MS). Such portable devices can accurately track breath acetone concentration to become an alternative to more elaborate breath analysis techniques.

The unprecedented medical achievements of the last century have dramatically improved our quality of life. Today, the high cost of many healthcare approaches challenges their long‐term financial sustainability and translation to a global scale. The convergence of wearable electronics, miniaturized sensor technologies, and big data analysis provides novel opportunities to improve the quality of healthcare while decreasing costs by the very early stage detection and prevention of fatal and chronic diseases. Here, some exciting achievements, emerging technologies, and standing challenges for the development of non‐invasive personalized and preventive medicine devices are discussed. The engineering of wire‐ and power‐less ultra‐thin sensors on wearable biocompatible materials that can be placed on the skin, pupil, and teeth is reviewed, focusing on common solutions and current limitations. The integration and development of sophisticated sensing nanomaterials are presented with respect to their performance, showing exemplary implementations for the detection of ultra‐low concentrations of biomarkers in complex mixtures such as the human sweat and breath. This review is concluded by summarizing achievements and standing challenges with the aim to provide directions for future research in miniaturized medical sensor technologies.

Critical to the feasibility of electrochemical reduction of waste NOx (NOxRR), as a sustainable pathway and to close the NOx cycle for the emerging NH3 economy, is the requirement of...

In nature, durable self-cleaning surfaces such as the Lotus leaf rely on the multiscale architecture and cohesive regenerative properties of organic tissue. Real-world impact of synthetic replicas has been limited by the poor mechanical and chemical stability of the ultrafine hierarchical textures required for attaining a highly dewetting superhydrophobic state. Here, we present the low-cost synthesis of large-scale ultradurable superhydrophobic coatings by rapid template-free micronano texturing of interpenetrated polymer networks (IPNs). A highly transparent texture of soft yielding marshmallow-like pillars with an ultralow surface energy is obtained by sequential spraying of a novel polyurethane-acrylic colloidal suspension and a superhydrophobic nanoparticle solution. The resulting coatings demonstrate outstanding antiabrasion resistance, maintaining superhydrophobic water contact angles and a pristine lotus effect with sliding angles of below 10° for up to 120 continuous abrasion cycles. Furthermore, they also have excellent chemical- and photostability, preserving the initial performance upon more than 50 h exposure to intense UVC light (254 nm, 3.3 mW cm(-2)), 24 h of oil contamination, and highly acidic conditions (1 M HCl). This sprayable polyurethane-acrylic colloidal suspension and surface texture provide a rapid and low-cost approach for the substrate-independent fabrication of ultradurable transparent self-cleaning surfaces with superior abrasion, chemical, and UV-resistance.