Phosphate-solubilizing bacteria (PSB) are significant plant growth-promoting rhizobacteria that enhance the growth of plants by solubilizing insoluble phosphates and facilitating their uptake. Rhodobacter sp. is one of the PSBs identified from the rhizospheric soil of Tectona grandis, and it can solubilize up to 80% of phosphates in in-vitro conditions. In the present study, nanoparticles along with PSB were given as treatments. The excellent nature of silica to uptake nutrients and stress tolerance makes it different from other nanoparticles. Plant based green synthesis of Silicon nanoparticles from Gigantochloa nigrociliata leaves developed the spherical shape with 349.7 nm in Scanning Electron Microscopy (SEM), peak at 1033.85cm^-1 in Fourier Transform Infrared Spectroscopy (FTIR), amorphous nature and surface area of 312.46 m²/g in X-ray diffraction (XRD) was recorded. The combination of both PSB and SiO2 showed the synergistic activity of 335×10^-1 Colony Forming Units (CFU). The present study shows that the mixture of 0.005% of SiO₂ and 5 gm. (50%) of Rhodobacter sp. acts as a better nano-biofertilizer. This results in the growth and improvement of Zea mays. This method provides an alternative to GMO crops, fertilizers, and traditional insecticides.