Recent advances in porous silicon based optical biosensors

Abstract

PSi structures have unique physical and optical properties, which are being exploited for a numerous biomedical applications including biosensing, bioimaging, tissue engineering, and drug delivery. Different PSi optical structures can be fabricated to improve the sensitivity of the optical measurements. A very high surface area per volume of PSi can be used for the higher loading of target analytes in a small sensor area, which helps in increasing sensitivity and allows the miniaturization of biosensor. The specificity of PSi biosensor to the target analyte can be inferred by immobilizing the corresponding bioreceptor such as DNA, enzyme, or antibody via different conjugation chemistries. Finally, PSi is biocompatible material that offers additional advantage in comparison to other sensing platforms for in vivo implantable biosensing applications. This paper reviews fabrication, surface modification, biofunctionalization, and optical biosensing applications of PSi structures with special emphasis on in vivo and PSi photonic particles biosensing.