Human beings live and work in close proximity to dangerous gases. Chemical accidents often cause considerable damages to human lives as well as properties and their short- and long-term impact on the environment can be high. Hence, diligent monitoring and management of these gases are of profound importance. In industries where chemical accidents pose potential explosions and health hazards, wired sensors are installed in strategic locations. In some industries, employees are required to carry with them portable sensing devices in addition. Still, achieving high spatio-temporal resolution is challenging, since dense deployments impede the mobility of employees, robots, or other mobile objects. In this paper, we propose the use of nanotechnology and wireless sensor networks for monitoring toxic gases. Nanotechnology offers the possibility of developing gas sensors having small form-factors and high sensitivity. Wireless sensor networks enable high spatio-temporal sensing, in-network processing, and multi-hop communications. The paper shares our experience with a wireless sensor network monitoring ammonia. The network consisted of 21 sensor nodes, four of which integrated arrays of ammonia sensors while the rest served as intermediate nodes.

Achieving and maintaining optimal oral health necessitates a comprehensive understanding of the complex bio‐adhesive and metabolic processes occurring within the oral cavity. These processes are significantly influenced by the intricate composition of oral fluids, particularly saliva and its resident microbiome. Currently available methodologies struggle to accurately monitor the dynamic and heterogeneous nature of key oral biomarkers, such as glucose. The development of miniaturized sensors for continuous and quantitative monitoring of clinically relevant salivary parameters represents a significant advancement in diagnostic capabilities. This work introduces an electrochemical sensor array designed for the continuous, quantitative monitoring of the clinically relevant and paradigmatic metabolite glucose. To address the challenges posed by the complex salivary environment, a surface modification strategy is implemented involving hybrid films of Prussian blue with chitosan and glucose oxidase enzyme entrapped within chitosan. The incorporation of chitosan, along with the further integration of zwitterionic polymer based on self‐polymerized dopamine (pDA) and 2‐ Methacryloyloxyethyl Phosphoryl Choline (MPC), facilitates the sensitive, selective, and reliable glucose monitoring in harsh salivary environments. Continuous amperometric glucose monitoring showcases the platform's capability for real‐time quantification, as increasing glucose concentrations correspond with elevated current signals. Pilot experiments show the sensors' capacity to precisely quantify salivary glucose levels and ascertain unknown concentrations, validated through the use of commercial glucometers. While the initial focus lies on glucose detection as a proof of concept, the final device integrates multiple electrochemical and potentiometric sensors. This advanced configuration enables the comprehensive quantification of several clinically relevant parameters in saliva. The development of multi‐sensor devices for continuous monitoring within the oral cavity holds immense potential: by unlocking deeper insights into the mechanisms driving the onset and progression of oral diseases, it will pave the way for further innovations in preventive dentistry.

Thyroxine (T4) is a key hormone regulating metabolic, cardiovascular, and neurodevelopmental processes, yet its clinical quantification still relies on centralized immunoassays that limit rapid or point-of-care monitoring. Here, we present a label-free biosensing platform based on silicon nanowire field-effect transistors (SiNW-FETs) functionalized with a T4-selective DNA aptamer via a 3-Triethoxysilyl propylsuccinic Anhydride (TESPSA)-mediated silanization approach, enabling a streamlined two-step modification for oriented immobilization. The biosensor achieves robust real-time detection of T4 across the physiological concentration range (5–30 pM), with a limit of detection of ~5 pM and a strong linear correlation between drain current and analyte concentration (R² = 0.9931). Specificity is confirmed using non-functionalized devices and estradiol as a non-target control. All measurements were performed in undiluted phosphate-buffered saline, representing a physiologically relevant ionic environment and demonstrating stable sensor performance under realistic buffer conditions. The dose–response behavior follows a Hill model, allowing extraction of binding parameters and confirming that the electrical signal originates from specific aptamer–target interactions. These results demonstrate that aptamer-functionalized SiNW-FETs provide a highly sensitive, selective, and miniaturizable platform for quantitative thyroid hormone monitoring, with strong potential for future point-of-care applications.