Opioid testing at workplace: a giant magnetoresistive nanosensor platform for the rapid and quantitative detection of morphine in saliva at the point of care

Morphine is an analgesic narcotic drug with a high risk for addiction. Testing standards require urine samples processed by central laboratories, leading to delayed results. Giant magnetoresistive sensors coupled with super paramagnetic nanoparticles offer a quantitative, sensitive, and low-cost solution for morphine detection in saliva at the point of care. The smartphone-controlled platform transmits results via Bluetooth, takes 35 minutes from sample to result, and delivers a lower limit of detection of 3.78 ng/mL and a dynamic range up to 500 ng/mL. The affordable and multiplexable GMR nanosensor platform enables this technology to be widely utilized for workplace drug testing.