Integrated Approaches for Development of Gas Sensors: From Nanomaterials and Simulated Environment to Application in Smart Cities

Reliable transition of laboratory-developed gas-sensing nanomaterials into environmental monitoring systems remains limited by the lack of integrated testing platforms capable of reproducing realistic operating conditions while providing automated, high-quality sensor characterization. In this work, we present a comprehensive framework for environmental gas sensor development centered on a custom-designed gas sensor chamber (GSC) and its connection to standalone measuring stations (sMSs) intended for smart city air quality monitoring. The GSC was developed as a dedicated platform for controlled evaluation of sensing nanomaterials through automated regulation of temperature, relative humidity, gas concentration, and pressure, combined with impedance measurements over a broad frequency range (10 Hz–100 kHz). The system integrates dedicated chamber hardware, environmental control loops, an LCR/impedance-based measurement unit, and in-house software for instrument control, data acquisition, synchronization of environmental and impedance data, and post-processing with visualization and correlation analysis. The functionality of the platform was demonstrated using graphene oxide-based nanocomposites deposited on interdigital electrodes and tested under variable parameters of temperature, humidity, and carbon monoxide concentration. The chamber enabled stable and reproducible extraction of frequency-dependent sensor responses and identification of optimal operating conditions for selected materials. Building on these results, the same sensing concept was translated into an energy-autonomous sMS architecture based on modular interdigital sensor elements, impedance-based indirect gas quantification, remote communication, and photovoltaic power support. By integrating material evaluation, environmental simulation, automated data handling, and field-oriented station design within a single workflow, the presented approach bridges the gap between laboratory gas sensor research and practical deployment in distributed smart city monitoring networks.