Graphene oxide SPR sensor shows low-cost potential for detecting mercury, lead, and zinc in water

Researchers have computationally designed a surface plasmon resonance (SPR) sensor using a graphene oxide sensing layer on an aluminum-based stack to detect trace heavy metals in water. The simulation shows angular sensitivities up to 338 degrees per refractive index unit and detection limits around 10^-5 RIU for mercury, lead, and zinc. The design uses aluminum instead of gold to reduce cost, with an aluminum oxide layer to prevent oxidation. However, the sensor has not been fabricated or tested on real water samples, and the detection limit is an optical metric, not a validated concentration threshold. Real-world interference from other ions, pH, temperature, and organic matter remains unaddressed. If validated experimentally, this could enable affordable water quality monitoring for heavy metal contamination.