Qualitative analysis of heavy metals in onion epidermal cells by near-field microwave microscopy

Near-field microwave microscopy has the ability to penetrate into the sample and achieve the detection of electromagnetic properties inside the object, which is the basis for the detection of physical and chemical properties inside the cell and the imaging of the surface morphology. We propose a method to qualitatively analyze the presence or absence of specific heavy metal ions inside the cells by measuring the quality factor $Q$ of normal cell samples and those containing heavy metal ions using near-field scanning microscopy. The quality factors $Q$ in the test of the two kinds of cells are compared. Results show that quality factor $Q$ of the cells can be distinguished, both in the comparison of the same plant cells and the comparison of different plant cells. The qualitative distinction between normal cells and polluted cells containing heavy metal ions can be achieved.