Sensors are devices that detect or quantify a physical or chemical property of interest. They inform many of the decisions in our lives. They help diagnose diseases, guide the care of agricultural crops and livestock, and provide real-time information on health status and activity through smart watches. The 2026 Bioanalytical Sensors Gordon Research Conference and Gordon Research Seminar will bring together experts and early-career researchers from around the world to address grand challenges in health monitoring and diagnostic development. This conference will serve the sensing community by promoting interactions and learning across a broad, global group of scientists, engineers, and practitioners at various stages of their careers. The topics covered and collaborations forged at this 21st Bioanalytical Sensors GRC/GRS will catalyze advances that can advance national health, prosperity, and security. Sensors designed for analytical performance provide the accurate datasets needed to mitigate the spread of infections, inform healthcare decisions, and maintain food safety and security. When designed for laboratory use, these sensors can provide molecular insights into the underlying biological processes that present as healthy or distressed phenotypes in the clinic or the field. When designed with the user interface in mind, sensors can provide individuals with health-related metrics and track progress toward a healthy lifestyle through smart, integrated platforms that record and analyze data collected by these sensors. When designed with cost in mind, sensors can be readily deployed to all communities and to benefit the health of all. Because of the prominent role sensors play in our lives, establishing a community of experts to discuss outstanding challenges in biosensing and potential approaches to address them is key to improving measurement accuracy across biomedical research, health, food security, forensics, and related fields. The 2026 Bioanalytical Senso