New Cheap Sensor Detects THC in the Air

A fresh idea tackles a growing need. As more places allow cannabis use, people want to know how much THC is in the air. This new tool can help by spotting tiny amounts of the active compound. The sensor works differently from older gadgets. It uses a special screen‑printed graphene electrode that has manganese dioxide on it. A thin film of acrylic acid holds a dye called Fast Blue B. Together, they pull THC molecules toward the surface and lock them in place. Testing shows the device is precise. It can measure THC levels from 25 to 250 parts per billion, with a lowest detectable amount of 4. 5 ppb. The response changes by only about five percent when other chemicals are present, meaning it is very selective.To prove it works in real life, scientists compared the sensor’s readings to those from standard lab machines like HPLC and GC‑MS. In smoke from cannabis cigarettes, the sensor found THC, but it ignored ordinary tobacco smoke. This shows it can tell the difference between legal and non‑legal products. Because it is inexpensive, easy to use, and disposable, the sensor could become a common tool for checking air quality around places where cannabis is sold or consumed. It offers a simpler alternative to costly lab equipment, making monitoring more accessible.