Next-Generation Chemical Sensors: The Convergence of Nanomaterials, Advanced Characterization, and Real-World Applications

Chemical sensors have undergone transformative advances in recent years due to the convergence of nanomaterials, advanced fabrication techniques, and state-of-the-art characterization methods. This review analyzes developments from 2019 to 2025 in the design and application of next-generation chemical sensors, with a focus on the United States as a key driver of global innovation. Nanomaterials such as graphene derivatives, MXenes, carbon nanotubes, metal–organic frameworks, and hybrid composites have enabled unprecedented sensitivity and selectivity, achieving detection limits down to parts-per-billion and even parts-per-trillion levels for gases, ions, and biomolecules. Concurrently, additive manufacturing, miniaturization, and flexible electronics have facilitated the creation of wearable, stretchable, and implantable sensors, expanding their utility in healthcare diagnostics, environmental monitoring, food safety, and industrial process control. Advanced characterization techniques including in-situ spectroscopy and high-resolution microscopy have elucidated interfacial mechanisms, guiding rational material design. Despite these advances, challenges remain in terms of scalability, reproducibility, long-term stability, and regulatory compliance, while data privacy emerges as a key concern for IoT-integrated sensing networks. Future perspectives highlight the integration of artificial intelligence and machine learning for real-time data interpretation, development of green and biodegradable materials, and the convergence of multidisciplinary approaches to address societal needs. Overall, nanomaterial-enabled chemical sensors are poised to become essential tools for advancing public health, environmental sustainability, and industrial innovation.