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硝酸盐在地下施药后的空间分布。简单地说，肥料管理工具的市场吸引力来自每年硝酸盐肥料的施用量(约占全部施肥量的59%，国内为1229万吨)，以及估计的30%的废品率。这种损失的投入超过4.42亿英亩的美国农田导致了巨大的运营支出，与产量或盈利增加几乎没有关联，并导致美国和国外的水道和地下水退化。在未来30年内将我们的粮食生产能力提高一倍，同时减少农业非点源污染对环境的影响，已被确定为重大挑战之一。面向化学和工程科学。在全球范围内，开发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优化产量和实现粮食生产自给自足的新方法，而不考虑偏远地区或实验室的可获得性。此外，原位硝酸盐测量工具将为在地下水修复活动中跟踪和绘制有机污染物羽流提供重要工具。这一小型企业创新(SBIR)第二阶段项目将实现晶片级处理和中试规模生产包含一种新型硝酸根离子分子受体的化学改性场效应晶体管(ChemFET)。这些敏感成分将被整合到受专利保护的模块中，实现对土壤中硝酸盐的直接、现场测量，而无需样品前处理。由于竞争介质中离子载体的局限性，特别是在常见氯离子存在的情况下，目前测定土壤中硝酸根离子的方法都需要对样品进行现场或实验室前处理。第一阶段的开发表明，通过结合对硝酸盐具有高灵敏度和专一性的分子受体，由含有这些分子受体的化学FET组成的系统产生的传感器能够在氯浓度高3个数量级的情况下以百万分之一位数(Ppm)的分辨率报告硝酸盐浓度。第二阶段将开发与分子受体兼容的晶片级沉积工艺，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二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.