Development of an atmospheric pressure plasma-based OES device for in-situ mapping of Cd and related elements in plants

We have developed an innovative optical emission spectrometry imaging device integrating a diode laser for sample introduction and an atmospheric pressure plasma based on dielectric barrier discharge for atomization and excitation. By optimizing the device parameters and ensuring appropriate leaf moisture, we achieved effective imaging with a lateral resolution as low as 50 μm. This device allows for tracking the accumulation of Cd and related species such as K, Zn, and O2+∙, in plant leaves exposed to different Cd levels and culture times. The results obtained are comparable to established in-lab imaging and quantitative methods. With its features of compact construction, minimal sample preparation, ease of operation, and low limit of detection (0.04 μg/g for Cd), this novel methodology shows promise as an in-situ elemental imaging tool for interdisciplinary applications.