Glow Discharge Optical Emission Spectroscopy Elemental Mapping (GDOES-EM) for Nanoparticle Characterization in Plant Tissues

Nanoparticles (NPs) have been shown to have many applications in fields such as medicine, industry, and agriculture. Due to their unique properties, NPs have been the subject of vigorous study. For instance, due to the increased NP prevalence, work has been underway to understand their impact on the growth and development of plants, which is of particular interest in the field of agriculture. Several techniques are available to analyze nanoparticles and their uptake by plants, each that feature their own advantages and disadvantages. Glow discharge optical emission spectroscopy (GDOES) elemental mapping (EM) is an ultra-high-throughput method that allows for simultaneous quantitative and qualitative multi-elemental analysis and has the potential to be more accessible than other methods. GDOES also avoids the arduous time and resource requirements imposed by the need for tissue encapsulation as is required in other techniques. Herein, GDOES-EM was explored in gathering elemental identification, concentration, and distribution information from silver NPs depositions on pristine and dried plant samples. Competitive spatial resolution and limits of detection were obtained in tens of seconds. The select applications demonstrate the utility of this technique in solving problems where other techniques would be more expensive, more time-consuming or would even fail. Moreso, this is the first time a pristine biological soft tissue is analyzed, or mapped, through GDOES, thus opening the door to many other applications relevant to biological and medical sciences.