Citrus greening (Huanglongbing) is an invasive disease in citrus plants that is devastating the largest citrus industry in the United States. This disease causes significant crop loss for citrus growers because of the increased premature fruit drop and the reduced fruit quality. There is a need for investigating the low-cost, easily accessible, and efficient nanomaterials which have potential applications in treating the Huanglongbing (HLB) disease. One of the potential candidates is a zinc oxide (ZnO) nanomaterial which has the ability to produce reactive oxygen species as well as Zn ions in solution. Theoretical modeling and simulations at multiscale can provide insights into the mechanism of producing reactive oxygen species and the interaction between ZnO particles and molecules (simple to complex).

The zinc sulphide (ZnS) quantum dots (QDs) and the Mn-doped ZnS QDs are interesting materials that can be used for the cost-effective, sensitive, and selective detection of molecules in plant cells and for the good antibacterial agents. The Mn-doped ZnS QDs with smaller sizes (~3 nm) may offer the good antibacterial activity and the selectivity for detecting metal ions or other chemical components in biomolecular complex. We are interested in studying the ZnS QDs and the Mn-doped ZnS QDs conjugated with organic molecules (hybrid organic–inorganic material) for the biological applications.

Huanglongbing (HLB), also known as citrus greening, has gained renown as a most serious threat to citrus industry worldwide. First observed more than a hundred years ago in Asia, the disease is a challenging threat due to its complexity, its destructiveness, the susceptibility of most commercial citrus species. HLB is associated with three species of the genus Liberibacter: Candidatus Liberibacter asiaticus, Candidatus Liberibacter africanus, and Candidatus Liberibacter americanus. Trees infected with HLB have blotchy mottling of leaves, shoot stunting, and gradual dieback of branches. They produce small, deformed fruits with bitter juice, which is unmarketable. Infected trees do not die right away; they can remain in a steady state of decline for several years. The long-term goal of the project is to develop an industrially-viable, easily accessible multifunctional bactericidal technology (MS3T) for treating HLB, potentially offering a path towards the sustainable agriculture. The MS3T product is based on the zinc-based ternary solutes (TSOL). Our focus is to study the structural property, electronic and vibrational properties of the Zn-based TSOL in various local environment as well as the interaction of TSOL with biomolecules employing computational techniques based on the classical and quantum mechanical theoretical approaches.

TiO2 is a transition metal oxide and finds applications in pigments, additives, catalysts and construction materials. However, some experimental studies have uncovered the potential cytotoxic effects of transition metal oxide nanoparticles which include changes in cell morphology, mitochondrial functions, membrane leakage, necrosis and apoptosis. With their extensive use in a wide array of applications it has become of vital importance to understand their potential cytotoxic effect to design them for safe applications. Molecular dynamics (MD) simulations can help shed some light on the nature of the interaction when the metal oxide nanoparticle first encounters the cell membrane. Through atomistic MD study, we assess the effect of the TiO2 nanoparticle on the structural, mechanical and dynamical properties of neutral DOPC and charged DOPG bilayers. These preliminary studies pave the way for a more detailed study into the differential interactions of various other metal oxide nanoparticles with mixed lipid bilayers.