Grant: Discovery Grants Program - Individual

Global challenges in health (cancer, heart disease) and energy (renewable energy sources, efficient devices) urgently require sustainable solutions. Material scientists are designing the tools essential in both contexts. Materials that contain rare-earth (RE) elements are known for their outstanding optical properties, such as upconversion (UC, emission of visible light under near-infrared (NIR) excitation) and the emission of NIR light under NIR excitation. In addition, some of the rare-earths exhibit excellent magnetic properties, making them promising candidates for multifunctional optomagnetic probes. Despite the high promise, key challenges in using RE-based nanoparticles (RE-NPs) impede their transition from the lab bench to real-life applications. Low photoluminescence efficiency and the need for more reliable and efficient synthesis routes require ongoing research efforts. We address existing challenges through innovative synthesis pathways, the use of unconventional hyperspectral imaging, and our insights into critical structure-property relationships. Motivated by the manifold application potential of RE-NPs, yet, existing barriers, the overarching goal of the research program is to develop next-generation RE-based nanophosphors as multifunctional nanocarriers. Our short-to-mid-term goals include (i) the establishment of straight-forward microwave-assisted synthesis protocols, guaranteeing the fast and reliable access to a large library of RE-NPs of controlled chemical composition, size, morphology, and crystalline phase, thus, engineered optical and magnetic properties. (ii) By choosing appropriate RE3+ ions and host materials (fluorides, oxides), we target the design of RE-NPs with enhanced upconversion and NIR emission (UV-vis to 1870 nm) as well as novel, longer NIR-wavelength-emitting RE-NPs. NIR emissions centered at 2200 nm (the so-called 4th biological transparency window) were recently suggested for bioimaging applications, but access to suitable nanoprobes and understanding of their structure-property relationships is very limited. The proposed design of novel NIR probes holds large promise to open the door to innovative applications in bioimaging and beyond, e.g., multiplexing or encoding. (iii) We will leverage the magnetic properties of the RE3+ ions into multimodal imaging probes to study nano-bio-interactions and implement RE-NPs in more powerful diagnostic tools (i.e., optical probes with additional magnetic resonance imaging capability, including chemical sensitivity for biological sensing). In parallel, this program seeks the design and understanding of innovative magnetic RE-NPs for application in e.g., more efficient storage devices. Ultimately, it is our long-term goal to design next-generation RE-NPs for optomagnetic bioimaging, more efficient storage and optoelectronic technologies. As such, the outcomes of this program will address global challenges in health and energy, benefitting our society.