Diatom based biosensor for high sensitive fluorescence detection based on a spin-on glass bonding technique

Diatom, with delicate nanoscale porous SiO₂ structures, has a promising application in biosensing. We bond diatoms with SiO₂ substrate using spin-on glass (SOG) as interlayer to acquire a high performance diatom based fluorescence detecting biosensor. As diatoms can improve proteins density, diatom based biosensors have higher sensitivity compared with traditional protein sensors. This biosensor is fully made of SiO₂ which can be modified for biomass attachment. Nanoscale structures of bonded diatoms are better preserved than any related works. The highest bonding strength is 0.6 MPa. Human immunoglobulin G (IgG) is attached on traditional protein sensors and diatom based biosensors as antibody. After hybridized with Cy3-goat anti-human IgG, the diatom based biosensor provides a fluorescence detection signal 2.5 times higher than the traditional one. Given improved fluorescence detecting sensitivity, this new kind of diatom based biosensor can be widely used for various protein detections.