## 2 Progress in Various Nanotechnology Disciplines
### Environmental Nanotechnology  
[PERSON] (University of Florida, Gainesville, FL) presented research with an overall goal to develop a sensor-analytics point solution (SNAPS) for monitoring soil nitrogen status (NH4\({}^{+}\) and NO3\({}^{-}\) ions) to be used for providing on-farm decision support [73]. Soil is a living resource that is vital to global function, and acts as an interface between agriculture and the environment. The key indicator in soil, nitrogen, is spatially and temporally dynamic, varying widely with soil type and local conditions. Nitrogen is required to sustain agricultural productivity and maintain ecological function. While many tools have been developed for tracking soil nitrogen status, there are few commercial sensors with specificity and durability for long-term monitoring and decision support. Laser-scribed-graphene (LSG) electrodes were first fabricated using a biomimetic entropic patterning technique recently developed by the McLamore lab at UF, and then the electrodes were functionalized with ion-selective polymer composites [74]. Various hardware configurations were developed for providing wireless functionality in scenarios of short-term and long-term monitoring [75], and sensors were validated in laboratory soil column studies based on signal acquisition with a smartphone. A smartphone-based analytical tool was developed for determining whether water meets runoff guidelines using block coding (Thunkable). The sensors demonstrated near Nernstian sensitivities (51 to 54 mV/decade) with a detection limit in the range of 20 to 25 uM, and low drift (1 to 5 uV/hr) [74]. A proof-of-concept SNAPS tool is currently being tested in field studies and the results of these trials will be used to improve the hardware/softwareconfiguration for the tool prior to large scale field testing. SNAPS have the potential to help resource managers or growers better manage fertilizer applications by providing on-farm decision support.  
[PERSON] (University of Florida, Gainesville, FL) presented a low-cost and quick-analysis framework by coupling inexpensive nanosensors for inorganic mercury determination with a risk model on a mobile device to equip communities with real-time information for decision support. Mercury is a dangerous neurotoxin that can cause a plethora of health effects at levels as low as two parts per billion for inorganic forms in drinking water [76]. These effects are often heightened in low-income artisanal small-scale gold mining communities where there is less control over environmental and occupational exposure and the resources to monitor mercury pollution [77]. Standard laboratory techniques to test the water quality (e.g., atomic absorption spectroscopy) are accurate but expensive and impractical [78]. In addition to inconvenient sensing technologies for resource-limited settings, communities often lack post hoc analysis tools for characterizing the risk of contaminants [79; 73]. Electrodes were fabricated by laser scribing polyimide and decorated with nanometals, such as nanocuprous oxide, to create carbon-metal nanohybrid structures. The electrochemical behavior and sensor performance were analyzed via differential pulse voltammetry on a portable ABE-STAT potentiostat [75]. Distinct peaks of current as a result of the addition of mercury concentrations were linear from 0-1000 ppb with a response time of 1 min. The sensors were paired with a hazard quotient calculator application on a smart device to create a participatory monitoring effort for making informed decisions in the region. This information is being used to develop mitigation strategies and protect groups vulnerable to mercury toxicity. The methods for developing the carbon nanosensors and decision support tools do not require specialty equipment and are facile, economic, and quick, which makes this method useful for development in rural areas. Sensors, risk models, and decision support analyses present a new paradigm shift in participatory monitoring for disadvantaged rural communities.