Nanoenable agriculture has been rapidly developed. However, foliar application of nanofertilizers results in them dripping off the leaves, which would effectively limit their bioavailability. Herein, a nanocarrier method of using nanoporous SiO 2 (NanoSi) was found to enhance the adhesion of carbon dots (CDs) on crop leaf surfaces. Foliar application of NanoSi-CDs (10 mg•L −1 ) could significantly increase the net photosynthetic rate (Pn; 110.0−140.0%), fresh weight (327.1% in roots and 247.2% in shoots), and dry weight (212.0% in roots and 118.5% in shoots) of maize. Moreover, NanoSi-CDs showed a long-term promotion effect. Specifically, the Pn remained significantly increased on day 20 after spraying with NanoSi-CDs, whereas the CDs had no such effect at the same time. Furthermore, the rainfall simulation experiments demonstrated that the water resistances of NanoSi-CDs and CDs were 2.5 and 1.5 cm, respectively. Compared with the control, NanoSi-CDs could increase the Pn by 22.3% on the 20th day after rainfall. Collectively, NanoSi nanocarriers can be a promising method to improve the bioavailability of engineering nanomaterials in sustainable agriculture.