Light-nutrition coupling effect of degradable fluorescent carbon dots on lettuce†
Abstract
The increasing application of carbon dots (CDs) inevitably leads to environmental leakage. To be environmentally friendly, degradable CDs will become a mainstream agricultural application in the future. We prepared three CDs with different functional groups. Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) analysis showed that –CC–H and CO groups on the CD surfaces are major sites for oxidative degradation of the CDs. The pyridine N is responsible for photoproduction of ˙OH and ˙O2−, which will self-induce degradation. By liquid chromatography-mass spectrometry (LC-MS) method, the routes for N-doped CDs degrading into carboxylic acid compounds, CO2, NH4+, and H2O are clearly illustrated. After spraying fluorescent CDs on lettuce leaves, only the group of lettuce that combined the light conversion function of N3-CDs and the final degradation products of N3-CDs exhibited a significant enhancement of the net photosynthesis rate by 1.13 times, acceleration of the ETR by 1.19 times, and improved expression of genes related to CO2 fixation in the C4 cycle and carbon assimilation in the C3 cycle.
- This article is part of the themed collection: Environmental Science: Nano Recent HOT Articles