Regeneration of titanium oxide nano-coated long-period grating biosensor

This work presents an application of sodium hydroxide (NaOH) as an effective method for regeneration of titanium oxide (TiO x ) nano-coated long-period grating (LPG) biosensor. Below 100 nm in thickness TiO x coating was deposited with atomic layer deposition (ALD) method on LPGs for enhancing their refractive index sensitivity up to 2912 nm/RIU in RI range 1.33-1.36 RIU. Next, the sensors were biofunctionalized in order to immobilize receptor (biotin) on their surface and used for selective avidin detection. After successful biofunctionalization process and avidin detection the sensors were washed in NaOH and biofunctionalized again. The proposed method for recovering the sensor does not cause decrease in its functional properties. As a result of the applied procedure the biosensor was fully regenerated.