Deyang Qu - US grants

With this award from the Major Research Instrumentation Program (MRI) and support from the Chemistry Research Instrumentation Program (CRIF), Professor Peter Geissinger from the University of Wisconsin-Milwaukee and colleagues Graham Moran, Arsenio Pacheco, Deyang Qu and Nicholas Silvaggi have acquired a 500 MHz Nuclear Magnetic Resonance (NMR) spectrometer. This spectrometer allows research in a variety of fields such as those that accelerate chemical reactions of significant economic importance, as well as the study of biologically relevant species. In general, NMR spectroscopy is one of the most powerful tools available to chemists for the elucidation of the structure of molecules. It is used to identify unknown substances, to characterize specific arrangements of atoms within molecules, and to study the dynamics of interactions between molecules in solution or in the solid state. The results from these NMR studies have an impact in synthetic organic/inorganic chemistry, materials chemistry and biochemistry. This instrument is located a general user facility managed by highly qualified scientists is an integral part of research, research training and teaching in the Departments of Chemistry and Biochemistry. The spectrometer helps in the overall mission by providing students with NMR knowledge and enable their success in the chemical/engineering workforce for many industries (chemical, pharmaceutical, biotechnological, engineering, environmental and others), government agencies and laboratories, educational and research institutions.

The award is aimed at enhancing research and education at all levels, especially in areas such as (a) enzyme mechanisms; (b) non-proteinogenic amino acid L-enduracididine; (c) multi-heme respiratory enzymes involved in the interconversion of ammonia and nitrite; (d) enantio- and stereospecific methods to synthesize antimalarial and antileishmanial bisindole alkaloids; (e) asymmetric catalysts for organic synthesis; (f) vitamin D receptor modulators; (g) reactivity and function of DNA and its application for DNA sequence detection and drug discovery; (h) energy technologies and (i) reagents, media, and processes for the separation of metal ions.

This PFI: AIR Technology Translation project focuses on translating a sensing platform, which is based on tin oxide nanocrystal-reduced graphene oxide (SnO2 NC-RGO) hybrid structures, to fill the need for a low-cost, fast, and ultra-sensitive method for hydrogen (H2) detection. Sensing hydrogen is important because it is very flammable if is mixed with ordinary air (due to the oxygen content in the air). Thus, a sensor is needed in applications requiring or containing hydrogen such as fuel cells, some batteries, hydrogen powered vehicles, etc.

This project will result in a prototype handheld device that combines the sensor chip with a digital meter for direct readout of test results; the H2 sensor chip is also adaptable to batteries, fuel cells, and existing air quality monitoring equipment for real-time H2 detection. This NC-RGO sensor chip has the following unique features: rapid response for real-time monitoring, micron-sized dimensions, high sensitivity, scalable fabrication, and wireless communication compatibility. Compared to current hydrogen sensors in the marketplace, these features provide fast response, superior sensitivity/selectivity, portability, low-cost, and facile connection with smart phones/devices.

This project addresses the following technology gaps as it translates from research discovery toward commercial application. The NC-RGO sensing platform will be further improved in order to realize the low-cost, reliable, ultrasensitive H2 detection for various applications (e.g., H2 fuel cells, vehicles, lead-acid batteries, and air quality monitoring for indoor spaces) associated with H2. Various sensor characteristics will be investigated and validated, including sensor sensitivity, selectivity, long-term stability, performance in different operating conditions (e.g., various humidity values), and calibration methods. Insights into the NC-RGO sensing platform will advance the understanding of the interaction mechanism between gas molecules and low-dimensional materials in hybrid structures. Such understanding can further contribute to the design of nanomaterials with desirable properties to identify active sites and rates of catalytic reactions on metal/metal oxide NCs and to provide guidelines for performance enhancement through engineering properties of NCs. In addition, personnel involved in this project, undergraduates (including underrepresented students) and graduate students, will receive innovation and entrepreneurship training experiences through interacting with industrial partners and additional entrepreneurship training through I-Corps.

The project engages NanoAffix Science LLC., Johnson Controls, and A.O. Smith to augment the project impact through accelerated commercialization of the resulting H2 sensing technology.

Low-cost sensors for real-time monitoring of contaminants in water, such as toxic heavy metal ions, could provide early warning of contamination, thereby improving drinking water safety and protecting public health. A graphene-based water sensor platform is thus explored for rapid, sensitive, and selective detection of various water contaminants, overcoming limitations of current sensing technologies such as slow detection and inadequate sensitivity. However, the commercialization of such a sensor system is limited by its relatively high manufacturing cost due to the batch processing that involves traditional lithographic electrode fabrication and multiple manual post-electrode fabrication processes. This award explores a low-cost customized inkjet printing process for manufacturing of graphene-based water sensors. The research entails engineering various inks and modifying the standard inkjet printing process to produce the complete sensor system, continuously. High throughput manufacturing of the nano-enabled water sensing systems reduces their cost and enhances market acceptance. The research outcomes provide the rationale for substrate selection and treatment, scalable methods for producing various inks suitable for inkjet printing, and process models for customized inkjet printing. Project results could be used for many other applications such as solar cells, lithium-ion batteries, and supercapacitors, enabling low-cost manufacturing of a wide range of printable electronic devices. The project trains diverse student populations including women and minorities on scalable nanomanufacturing, nanodevice design and real-time water-sensing technologies through hands-on research experience, a course module, and enriching existing curricula.

The sensor platform is based on a field-effect transistor structure with reduced graphene oxide as the sensing channel and gold nanoparticles as anchoring sites of selective chemical probes. A major challenge for inkjet printing is the customization of the inkjet printing process for a specific device or system architecture. Customization involves engineering suitable inks, modifying the standard printing process parameters, and integrating components at different scales. The research team aims to close this knowledge gap by exploring inkjet printing of the entire graphene-based sensor system to enable the large-scale production via high throughput roll-to-roll nanomanufacturing of the sensor devices, which should result in low cost. The scalable nanomanufacturing of inks for all sensor components: electrode, sensing material, and probe, and their printing and integration into water sensor systems are investigated, together with methods for selecting and treating polymer substrates and customizing inkjet printing parameters. The sensor performance is validated in industrial testbeds through collaboration with A. O. Smith Corporation and NanoAffix Science, LLC. The project leads to a low-cost, high-yield scalable nanomanufacturing platform for graphene-based water sensor systems and other flexible electronic systems that can be readily commercialized by industrial partners.