Malayil Gopalan Sibi

Abstract

The efficient and precise detection of trace-level volatile organic compounds (VOCs) is critically important for environmental monitoring, industrial safety, and public health. In this context, single-atom (SA) materials have emerged as a new frontier in sensor technology, offering unparalleled atom and energy efficiency, along with maximal exposure to active sites. Compared to conventional nanoparticle and bulk sensors, SA-based platforms exhibit superior sensitivity, selectivity, and tunability. This review presents a comprehensive overview of the advances in single-atom engineering (SAE) for VOC detection. We systematically discuss the design principles, fabrication methods, and sensing mechanisms of various SA-based sensors, including chemiresistive gas sensors (CGS), metal oxide semiconductors (MOS), microelectromechanical systems (MEMS), field effect transistors (FETs), and electrochemical sensors. Special attention is given to the roles of heteroatom doping, vacancy engineering , and support interactions in modulating the sensing performance. This review also highlights how advanced spectroscopic tools provide insight into SA-analyte interactions and how computational approaches, particularly density functional theory (DFT) and emerging machine learning (ML) techniques, aid in the rational design of next-generation sensors. Finally, we outline the current challenges and propose future research directions aimed at achieving scalable synthesis, long-term stability, and real-world deployment of SA-based VOC sensors. This review aims to guide future innovations in SA sensor technologies, setting the stage for trans-formative advances in VOC detection.