基于3D微纳结构材料可控组装的全固态水产养殖氨氮及亚硝酸盐传感器研究

High density aquaculture can provide high quality protein for human. However, fishes will suffer from the relatively high concentrations of ammonia nitrogen and nitrite, which come from the fish waste, metabolic products of microorganisms and feed remnants. Relevant research shows the maximum concentration of ammonia nitrogen and nitrite in aquaculture water that fishes usually can bear is only 0.025 mg/L and 0.1 mg/L, respectively. So there is an urgent demand for development of high sensitive, selective, stable and low-cost micro sensors for fast and sensitive detection of trace ammonia nitrogen and nitrite in aquaculture water...In our study, all-solid-state ion selective electrodes (ISEs) are proposed and prepared based on controllable assembly of the novel 3D micro-nano structured materials for detection of aquaculture ammonia and nitrite. The project will mainly focus on the following research contents: 1) The study on the synergistic effects of high redox capacitance of conducting polymers and high double-layer capacitance of graphene for effective sensing of ammonia nitrogen and nitrite, and the model of ion-to-electron transduction will also be built; 2)The key technologies for controllable assembly of the novel 3D miicro-nano structured materials will be explored, such as hydrogen bubble templated fabrication of nanoporous electrode substrate, one-step electrochemical deposition of solid contact of conducting polymer-reduced graphene oxide, and deposition of ion selective film by using electronic spray. The characterization of nanoporous electrode substrate, solid contact and ion selective film by SEM, TEM, XPS, XRD and TGA will be carried out; 3) The all-solid-state ammonia nitrogen ISE based on “nanoporous copper- graphene/PEDOT: PSS-ammonia ion selective film” and “TiO2 nanotubes array electrode-graphene/PEDOT--ammonia ion selective film” will be optimally fabricated. Also, the all-solid-state nitrite ISE based on “nanoporous Ag electrode- graphene/polyaniline-nitrite ion selective film” will be delicately prepared. In addition, the performances of all-solid-state ammonia nitrogen sensors and all-solid-state nitrite sensor will be tested. Especially, we will lay emphasis on the study of the stability and anti-interference performance; 4) The integrated sensing unit including all-solid-state ISEs and all-solid-state reference electrode will be developed for on-line monitoring of aquaculture ammonia and nitrite; 5) The reliable measurement technologies for weak potentials of all-solid-state ammonia ISEs and all-solid-state nitrite ISE. ..The sensitivity of sensors can be improved by nanoporous substrate, direct electron transfer of graphene. The stability of sensors can be promoted by the high double-layer capacitance and hydrophobicity of graphene. Additionally, the stability of ion selective films can be enhanced by the mechanical properties of graphene, as well as the increased binding force between the solid contact and ion selective films deposited by using electronic spray. The proposed sensors with high performance, especially the nitrite ISEs will fill in the blanks of China market. This study will promote the healthy development of China aquaculture, and the technical level of the internet of thing (IoT) based on advanced sensors for aquaculture water quality monitoring.

针对工厂化高密度水产养殖过程中由于鱼类排放废物、微生物分解有机物和残饵等易造成水中氨氮、亚硝酸盐浓度过高而威胁鱼类健康生长这一现状，迫切需要研制高灵敏、良好选择性、高稳定、低成本的氨氮、亚硝酸盐传感器，以实现养殖水体中低浓度氨氮和亚硝酸盐的快速、灵敏检测。课题在国内外相关研究基础上，创新性提出基于可控组装新颖3D微纳结构材料的全固态氨氮和亚硝酸盐传感器，解决传感器灵敏度和稳定性等关键难题。研究内容主要包括：基于“氧化还原电容-电双层电容”协同作用的离子浓度高灵敏感测机理和建模；高性能3D微纳结构材料体系可控组装关键技术及表征分析；基于“纳米多孔基底电极-固体接触（石墨烯-导电聚合物）-离子选择性膜”的氨氮、亚硝酸盐传感器的制备及性能测试；微弱传感信号可靠检测技术及传感器应用试验研究等。提出研制的高性能全固态氨氮、亚硝酸盐传感器，特别是全固态亚硝酸盐传感器在我国尚属空白，具有广阔的市场前景。

针对工厂化高密度水产养殖过程中由于鱼类排放废物、微生物分解有机物和残饵等易造成水中氨氮、亚硝酸盐浓度过高而威胁鱼类健康生长进而造成经济损失这一现状，本课题研制了高灵敏、良好选择性、高稳定、低成本的全固态氨氮、亚硝酸盐传感器，可以实现养殖水体中低浓度氨氮和亚硝酸盐的快速、灵敏检测。课题在国内外相关研究基础上，创新性提出基于可控组装新颖3D微纳结构材料的全固态氨氮和亚硝酸盐传感器，解决了传感器灵敏度和稳定性等关键难题。研究内容主要包括：探讨了基于“氧化还原电容-电双层电容”协同作用的离子浓度高灵敏感测机理并进行了建模；建立了高性能3D微纳结构材料体系“石墨烯-导电聚合物-金属纳米粒子”的可控组装制备关键技术及表征分析方法；形成了高稳定离子选择性膜的制备技术（包括电纺，静电喷雾，喷印等）及性能测试方法；搭建了微弱传感信号可靠检测嵌入式系统，开发了基于手机的手持式传感仪；进行了传感器的应用试验研究，对氨氮及亚硝酸盐离子的检测范围均为10-7-10-1 M，下限则分别达到 6.4×10-8 M 、7×10-8 M，优于已报道的同类传感器。研究成果入选了2019年农业科技成果直通车重点推荐项目。本课题研发的基于丝网印刷电极的全固态氨氮及亚硝酸传感器具有可批量制备、性能重复性好、成本低等优势，已在多家水产养殖企业获得示范应用。在成果方面已发表/录用SCI/EI收录论文7篇，另有3篇论文已投稿SCI期刊；申请发明专利6项，获得授权4项，软件著作权6项，获得传感器性能鉴定证书3项。本课题研制的高性能全固态氨氮、亚硝酸盐传感器在我国尚属空白，在水产养殖、环境监测等领域具有广阔的市场前景，有助于推动我国智能传感器在智慧农业的发展。