Pollen derived blue fluorescent carbon dots for bioimaging and monitoring of nitrogen, phosphorus and potassium uptake in Brassica parachinensis L.

Abstract

Carbon dots (CDs), synthesized from biological sources, have attracted attention in bioimaging and bioscience due to their low cytotoxicity, water-soluble nature, and biocompatibility. However, there are a few reports on the absorption of elements and tracking the transporting systems in plants. Herein, we report pollen-CDs synthesized by a hydrothermal method that emit blue light under excitation of UV light, which can be used to track the absorption of nitrogen, phosphorus, and potassium, and mark the biological transport systems in Brassica parachinensis L. The pollen-CDs were transported via the vascular system of Brassica parachinensis L., confirmed by the confocal images. TEM results demonstrated that the pollen-CDs were enriched in the periplasmic space, which helps to enhance the absorption efficiency of potassium and inhibit the accumulation of nitrates in Brassica parachinensis L. The hydroponic experiment results demonstrated that Brassica parachinensis L. had the highest yield of 42.90 mg when 3.5 mg L⁻¹ pollen-CDs were added to the nutrient solution. All the results demonstrated that the pollen-CDs have potential for application in hydroponically grown vegetables and biocompatible studies in vitro/in vivo imaging.