SBIR Phase II: Development and Commercialization of Nitrate-Selective Sensors for Precision Agriculture

该项目更广泛的影响/商业潜力都源于需要了解地下硝酸盐的应用后空间分布。简单地说，肥料管理工具的市场需求源于每年施用的硝酸盐肥料量（约占所有施用肥料的59%，国内1229万吨），以及估计的30%的浪费率。这种超过4.42亿英亩美国农田的投入损失导致了巨大的运营支出，与产量或盈利能力的增加几乎没有相关性，并且是美国和国外水道和地下水退化的原因。在未来30年内将我们的粮食生产能力提高两倍，同时减少农业非点源污染对环境的影响，已被确定为一个？大挑战？面对化学和工程科学。在全球范围内，开发一种低成本和通用的土壤质量探测器将为发展中地区提供一种新的方法，以优化产量并实现粮食生产的自给自足，而无论是否偏远或是否有实验室。此外，原位硝酸盐测量工具将为地下水修复活动期间跟踪和绘制有机污染物羽流提供重要工具。该小企业创新（SBIR）第2阶段项目将实现晶圆级处理和中试规模生产化学改性场效应晶体管（CHEMFET），其中含有硝酸盐阴离子的新型分子受体。这些敏感组件将被纳入受专利保护的模块中，实现直接，原位测量土壤中的硝酸盐，而无需样品预处理。由于竞争性介质中离子载体的限制，特别是在常见氯离子存在的情况下，目前用于测量土壤中硝酸根阴离子的方法都需要现场或实验室内对样品进行预处理。第一阶段的发展表明，通过纳入一个分子受体具有高灵敏度和特异性的硝酸盐，系统组成的CHEMFET含有这些分子受体产生传感器能够报告硝酸盐浓度在单位数百万分之一（ppm）的分辨率在3个数量级更大的氯化物浓度的存在下。第二阶段将开发与分子受体兼容的晶圆级沉积工艺，同时避免不兼容的掩模/去掩模工艺。最终，这一开发过程将证明这些传感器的可制造性，并为客户和最终用户在第2阶段完成时进行大规模分布式beta测试奠定基础。

The broader impacts/commercial potential of this project both stem from the need to understand the post-application spatial distribution of nitrate below ground. Simply put, the market pull for fertilizer management tools stems from the amount of nitrate fertilizer applied annually (~59% of all applied fertilizer, 12.29M tons domestically), and the estimated waste rate of 30%. This lost input over 442M acres of US farmland results in huge operational expenditures with little to no correlation to yield or profitability increase, and is responsible for the degradation of waterways and groundwater both in the US and abroad. Increasing our food production capacity by two-fold in the next 30 years while concurrently decreasing the environmental impact of agricultural nonpoint-source pollution has been identified as one of the ?Grand Challenges? facing the chemical and engineering sciences. On a global scale the development of a low-cost and universal probe for soil quality would offer developing areas a novel method for optimizing yields and enabling self-sufficiency in food production, regardless of remoteness or laboratory availability. Additionally, a tool for in situ nitrate measurement will offer an important tool for tracking and mapping organic contaminant plumes during groundwater remediation activities.This Small Business Innovation (SBIR) Phase 2 project will enable wafer-level processing and pilot-scale production of chemically modified field effect transistors (CHEMFETs) containing a novel molecular receptor for nitrate anion. These sensitive components will be incorporated into patent-protected modules that achieve direct, in situ measurement of nitrate in soils without sample preprocessing. Current methods for measuring nitrate anion in soil all require on-site or in-lab preprocessing of the samples due to limitations of the ionophore in competitive media, especially in the presence of common chloride anion. Phase I development showed that by incorporating a molecular receptor with high sensitivity and specificity for nitrate, systems comprised of CHEMFETs containing these molecular receptors yield sensors capable of reporting nitrate concentration at single digit parts per million (ppm) resolutions in the presence of 3 orders of magnitude greater chloride concentrations. Phase 2 will develop a wafer-level deposition process that is compatible with the molecular receptor while avoiding incompatible mask/de-mask processes. Ultimately, this development process will prove the manufacturability of these sensors, and provide the foundation for large-scale distributed beta testing by customers and end-users at the completion of Phase 2.