Miss Sheena Anne Garcia

PhD Candidate

The Hong Kong University of Science and Technology

PhD not only advances my technical expertise as a high-caliber researcher, but also enables me to be a well-rounded person. As a PhD candidate at HKUST, I learned how to be bright and have a positive disposition. Doing research may seem difficult because results do not always go as planned but my positive attitude allows me to work harder and discover new things. I grew to be aware that doing research requires dedicated efforts, and I am trying to overcome instant gratification. In the past, I could get frustrated by failures. But from lessons learnt, I gained more confidence when facing new challenges. I will take delight in sharing knowledge to others so I would also like to be a postdoctoral fellow and enter the academe in the future. I hope to be able to inspire others just like how my professors and how fellow researchers have inspired me

Investigation of nanomaterials’ safety through transpiration study in plants

Nanomaterials are defined as functional materials consisting of particulates with at least one dimension below 100 nanometers. Nanomaterials have unique and enhanced physical and chemical properties, which make them interesting in industrial and biomedical applications. However, there is one major bottleneck for nanomaterials, which negatively affects the market- --there is no complete knowledge on the possible effects these nanomaterials might have on the human body or the environment. This study will help better understand the transport of nanomaterials in plants (i.e., bioaccumulation or biodistribution) and the fate of nanomaterials when they are released into the environment. If nanomaterials can accumulate into the edible parts of the plant, humans may possibly consume them. If nanomaterials can undergo transpiration, humans may inhale them. To the best of the author's knowledge, this research is the first to comprehensively analyze nanomaterials in hazard assessment and safety by thoroughly characterizing the investigated nanomaterial and studying if they will undergo transpiration. Here, Chinese celery (Apium graveolens var. secalinum) was chosen as the plant model because it is short, less drought-tolerant, and has a high leaf surface area to maximize transpiration. Several typical nanomaterials, including silver nanoparticles, functional iron oxide nanoparticles, inert silica nanoparticles, carbon dots, and metal-organic frameworks, were used to study their absorption, transportation, and release. The results show that celery roots could absorb all nanomaterials and transport them into stems. Silver and silica nanoparticles tend to enter leaf tissue. Only silica nanoparticles are eventually released into the environment through the transpiration process.