Carbon Dot Nanozyme for Enhancement of Yield and Quality in Maize through Multimechanism Joint Effects

Maize production plays a crucial role in ensuring global food security. However, the utilization of nanozymes in enhancing maize yield and quality has rarely been reported. In this work, for the first time, the preparation and application of carbon dot (CD) nanozymes to improve maize yield and quality are presented. The Michaelis–Menten equation demonstrates that CD nanozymes exhibit excellent enzymatic kinetic characteristics, thereby possessing catalase-like enzyme activity. The enzyme-like activity of CDs effectively mitigates oxidative damage caused by the external environment in maize. Moreover, CDs have the capability to convert solar ultraviolet light into bright blue light, enhancing the levels of essential elements such as Mg, Fe, and Zn in maize. Consequently, this promotes chlorophyll synthesis and photosynthesis. Furthermore, confocal imaging verifies that CDs can easily penetrate maize cells and subsequently regulate the endogenous antioxidant enzyme activity of maize. This leads to a reduction in peroxidation metabolites of malondialdehyde and an increase in antioxidant small molecule substances such as glutathione and ascorbic acid (VC). The combined effects mentioned above significantly increase maize yield by approximately 20% in planting experiments while also improving its nutritional quality. This study sheds light on the potential application of nanozymes in enhancing the maize yield and quality.