Abstract
Surface plasmon utilized for biosensing applications has been demonstrated with high sensitivity. There are many types of surface plasmon biosensors today. In this research, we focus on a grating-based surface plasmon biosensor. The grating-based SP biosensor detects the biomolecule through interrogating the shift of the reflection spectrum. According to the simulation result by Finite Difference Time Domain (FTDT) method, we found that the bandwidth is generally related to the profile of the grating. In addition, we integrate microfluidic systems into the SPR chip. Microfluidic systems have the advantage of reducing the usage of specimen and facilitating the delivery of liquid through the entire detection process quickly and easily. After optimizing the concentration and process time of applying HbA1c-specific aptamers, we passed through 0~3 μg/μl of HbA1c, followed by injecting 0.025 μg/μl of HbA1c antibody. We observed the SPR wavelength shifts along with the concentrations of HbA1c, showing a good linear correlation. We also demonstrated that the detection system can be miniaturized for a portable apparatus.