SitS NSF-UKRI: Phytoelectronic Soil Sensing

该项目由科罗拉多大学、英国剑桥大学和USDA-ARS联合开展，研究目标是利用植物作为原位化学实验室，精确、密集和远程地测量土壤状态。土壤状态与植物中主要导水组织木质部含量之间的相关性已得到证实。在“审问植物”中，通过在植物茎中植入生物电子传感器，诱导木质部在其周围形成，并通过低功率无线电传输这些传感器的数据来分析木质部含量。这种方法将避免直接感知土壤的复杂性，而是检测维管液对根部周围土壤中化学和生物变化的化学反应。这些由木质木质部组织运输的液体处于负压状态，因此通常难以接近。因此，该项目将研究一些外科植入的再生技术，这些小传感器与嫁接接点的木质部组织相关联，就像目前在果树上常规使用的嫁接一样。整个小型传感器，包括植入电子元件和再生涂层，将以非常低的成本进行丝网印刷。丝网印刷配方和其他使能技术将通过开放科学框架与公众分享。通过国际BioMaker和OpenPlant项目，将资助的工具包分发给团队，进一步促进这些结果的公共使用。该研究将探索植物电子学的新领域，融合植物学用于生物识别，生物电子学用于化学传感，物联网（IoT）电子学用于通信，机器学习用于分类。该研究的目标是：1)利用活植物在可变条件下自主运行的固有鲁棒性，创造一种廉价的、潜在的可生物降解的土壤多变量传感平台；2)将这些植物与物联网结合起来，在物联网中，埋在地下的根提取土壤状态，并以化学方式将其传递给嵌入式多分析物、电子传感器，然后将这些数据数字化并中继到服务器，用于集成和机器学习；3)通过选择对特定化学、病原体或生态信号具有特异性的植物并将其作为工具，促进对土壤与生物圈相互作用的理解。该团队将通过以下方式实现这些目标：1)打印基于有机电化学晶体管阵列的多分析物传感器，这些传感器分别具有离子特异性膜的功能；2)为电子设备创建可打印的药物释放涂层，以促进手术植入传感器附近木质部组织的再生；3)将这些“芯片植物”连接到RFID或LoRA反向散射通信标签上，这些标签可以远程询问以检索数字化传感器的响应。在项目结束时，这些研究的结合应该能够对玉米地的土壤硝酸盐浓度进行每日监测，分辨率低至平方米。该项目通过“土壤信号”机会获得，这是一项合作征集，涉及美国国家科学基金会（NSF）的ENG/CBET和BIO/IOS部门，美国农业部国家食品和农业研究所（USDA NIFA）和以下英国研究与创新（UKRI）研究委员会：1)自然环境研究委员会（NERC）， 2)生物技术和生物科学研究委员会（BBSRC）， 3)工程和物理科学研究委员会（EPSRC）和科学技术设施委员会（STFC）。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

The research objectives of this project at the University of Colorado, University of Cambridge in the UK and USDA-ARS are to measure the state of the soil accurately, densely and remotely using plants as in situ chemical laboratories. Correlations between the state of the soil and the contents of the major water-conducting tissue in plants, the xylem, are well-established. Xylem contents will be analyzed in "interrogator plants" by implanting bioelectronic sensors in plant stems, inducing xylem to form around them and remotely communicating data from these sensors by low-power radio transmission. This approach will avoid the complexity of sensing the soil directly by instead detecting the chemical response of vascular fluids to chemical and biological changes in the soil around the roots. These fluids, which are transported by the woody xylem tissues, are under negative pressure and thus typically difficult to access. The project will therefore investigate a number of regeneration techniques for surgically implanted, small sensors such that these sensors become associated with xylem tissue in graft junctions, much like the grafting currently used routinely in fruit trees. The entire small sensor including implanted electronics and regenerative coating will be screen-printed for very low cost. Screen printing recipes and other enabling techniques will be shared with the public through the Open Science Framework. Public use of these results will be further fostered by funded kits distributed to teams through the international BioMaker and OpenPlant programs.The research will explore the new field of phytoelectronics, the convergence of botany for biorecognition, bioelectronics for chemo-sensing, internet-of-things (IoT) electronics for communication, and machine-learning for classification. The goals of the research are to 1) create an inexpensive, potentially biodegradable platform for multi-variate sensing of the soil utilizing the inherent robustness of living plants to operate autonomously in variable conditions; 2) merge these plants with the IoT in which buried roots extract and communicate soil state chemically to embedded multi-analyte, electronic sensors that then digitize and relay these data to servers for integration and machine learning; and 3) advance understanding of the interaction of soil and the biosphere by selecting plants specialized for specific chemical, pathogen or ecological signals and using them as instruments. The team will accomplish these goals by 1) printing the multi-analyte sensors based on arrays of organic electrochemical transistors individually functionalized with ion specific membranes, 2) creating printable drug-release coatings for the electronics that encourage regeneration of xylem tissue near the surgically implanted sensor, and 3) connecting these "chipped plants" to RFID or LoRA backscatter communication tags which are interrogated remotely to retrieve digitized sensor response. At program end, the combination of these studies should enable the soil nitrate concentration in a cornfield to be monitored daily with resolution down to square meters.This project was awarded through the "Signals in the Soil (SitS)opportunity, a collaborative solicitation that involves the ENG/CBET and BIO/IOS divisions of the National Science Foundation (NSF), the United States Department of Agriculture National Institute of Food and Agriculture (USDA NIFA) and the following United Kingdom Research and Innovation (UKRI) research councils: 1) The Natural Environment Research Council (NERC), 2) the Biotechnology and Biological Sciences Research Council (BBSRC), 3) the Engineering and Physical Sciences Research Council (EPSRC), and the Science and Technology Facilities Council (STFC).This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.