NanoAffix has exclusive access to an electronic sensing platform (platform technology) that can be used for the detection of various contaminants in water, such as heavy metal ions, bacteria, and nutrients.
The sensor is based on a field-effect transistor (FET) device with reduced graphene oxide (rGO) as the sensing channel and specific molecules attached to gold nanoparticles (Au NPs) as probes. The working principle of the sensor is that the rGO conductivity (usually measured in resistance) changes with the binding of chemicals/analytes to probes anchored on the Au NP surfaces, e.g., through chelate reactions with heavy metal ions. Therefore, the presence of the chemicals can be determined by measuring the sensor resistance change. Preliminary results have shown that the sensors can detect Pb2+ ions as low as 0.2 ppb, well below the maximum contaminant level (MCL) defined by the EPA for Pb2+ (15 ppb). Most importantly, the platform responds to Pb2+ in seconds, promising for real-time monitoring of water quality.
The rGO-Au NP-based sensing system has advantages of reliable probe immobilization, simple device structure, and rapid, sensitive, selective, label-free detection. This breakthrough technology allows real-time detection (no sample preparation) of poisonous contaminants with unprecedented sensitivity and specificity in field settings (outside a laboratory facility) for single point testing (e.g., handheld device) as well as for continuous monitoring (e.g., integrated into existing water equipment).