This simple paper sensor could change how we respond to future pandemics. And it costs only $1

The COVID-19 pandemic introduced everyone to the world of PCR tests and lateral flow tests but since then, a different type of testing has quietly been gaining momentum. Wastewater testing is a burgeoning method that has become key to monitoring public health in countries around the world. That’s because scientists can use it to track infections before people even show symptoms by analyzing sewage coming out of a local community, a university dorm, or an airport—giving health...