Recently, the rise of 2D materials has revolutionized sensor technology, offering cutting-edge solutions for both medical and environmental applications. These ultra-thin, highly sensitive sensors are transforming the way we monitor health and the environment, enabling real-time, precise measurements with minimal energy consumption. In the medical field, 2D-material-based sensors provide breakthroughs in non-invasive diagnostics, wearable health monitoring, and personalized treatment, significantly enhancing patient outcomes. They enable early disease detection; in some cases, continuous monitoring; and even real-time tracking of biomarkers in bodily fluids, reducing the need for invasive procedures. In environmental and food safety technologies, 2D-material-based sensors offer unparalleled detection capabilities for pollutants, water quality, and air monitoring, contributing to more effective environmental protection and sustainability efforts. Their high surface-area-to-volume ratio and exceptional electronic properties make them highly effective for detecting pesticide traces in food, toxic gases, heavy metals, and other contaminants in different concentration ranges. These sensors can play a crucial role in combating climate change, ensuring a safe water supply, and improving air quality. This presentation will examine the innovations behind 2D material sensors and explore how changing the size and thickness of these materials affects their sensitivity. Understanding these relationships is essential for optimizing sensors' performance and unlocking new applications across various scientific and industrial domains.