(163a) Heavy Metal Detection and Biochemical Sensing Using Plant Nanobionics Approach

Plants continuously exchange gases and fluids with the environment above and below ground. Through natural transpiration, they can continually extract water from subsaturated sources and move it across long distances with seemingly no energy input. These properties render plants compelling platforms for the extraction and detection of low concentrations of environmental pollutants in the soil. Several recent studies have attempted to produce genetically engineered plants for phytoremediation and detection of heavy metal contamination. However, such methods are typically limited to a narrow host of plant species amenable to genetic modification. In this work, we develop a nanoparticle-based approach to introduce non-native biochemical sensing capabilities to wild-type living plants. Using carbon nanotube optical sensors embedded in the leaf mesophyll, we demonstrate the detection of heavy metal contaminants through the root uptake of living plants. This approach is non-destructive and can be applied to a wide range of plant species, enabling real-time monitoring of environmental pollutants using plants as self-powered samplers of the environment. We also investigated the sensing mechanism and biocompatibility of the engineered nanosensor. In addition, the biosensing platform can also be used to monitor the endogenous signaling pathways elicited when plants are subjected to environmental stresses such as mechanical wounding. The nanobionic approach creates a new class of biomaterials that can serve as promising detection platforms for environmental remediation and agronomic applications.