<p>Bioelectronic devices enable real-time monitoring, diagnosis and treatment by blending biological processes with electronic technology. Through wireless connections, these systems could reduce reliance on hospital visits and offer remote care services to low-resource settings. However, there is a disparity in the biomechanical properties of conventional silicon-based systems and human tissue, which could impair tissue conformability and increase the risk of mechanical failure. Moreover, conductive polymers, despite being flexible, suffer from limited surface chemistry, lower electrical conductivity and poor long-term stability in physiological environments. Thus, wearable and implantable bioelectronics made of materials that enable stable, time-solved multimodal measurement of biophysical and biochemical signals in a miniaturized and subtle form factor are highly needed. In this Review, we examine the requirements, property matrix and role of low-dimensional materials in bioelectronic systems by device components for miniaturized, wireless and connected health care.</p>