A high sensitive SPR biosensor system utilizing gold nanorods

In this report, we propose a compact and highly sensitive biosensor device which utilizes gold nanorods, gold nanohole array film and photodiode array to detect the biomolecular reactions. In this device the Surface Plasmon Resonance (SPR) property of the gold nanorods and enhanced transmission and filtering property of nanohole array film is utilized to increase the sensitivity. The collective response of the biomolecular reaction with the gold nanorods and the gold nanohole array is captured by the photodiode. This system configuration utilizes the natural white light source to excite the SPR making it suitable for point of care biosensing of biomolecular bindings with pM levels of concentration. Two different photodiodes namely pinned (pinn) and n well-p substrate (nwell-psub) photodiodes were used to compare the performance of the system. Use of pinned photodiode had 2 times better performance advantage compared to nwell-psub photodiode.