Nanomaterials such as silica nanoparticles works as sensor when probe hybridized with the target sequence. Due to their large surface area to volume ratio, they can achieve rapid and low cost reactions. They can conjugate with a variety of biomolecules (Proteins, enzymes, peptides, and DNA) and used as fluorescence biomarkers to monitor biological events or identify and detect biological targets. Silica Nanoparticles offer a biocompatible, stable and stealthy. Surface of silica nanoparticles are modified by aminopropyltrimethoxysilane (APTMS) as a surface modification molecule for generating monolayer modification on the surface of silica (SiO ₂ ) nanoparticles. Bioactive molecules can be easily encapsulated by sol-gel polymerization by spray drying.Surfaced modified silica nanoparticles are used for drug delivery system and gene delivery systems.