In this paper the measurement light wavelength is changed to 1300 nm from 1500 nm because the light absorption of water
is much small at the wavelength of 1300 nm. Furthermore by employing slot waveguide, SiN core material with high temperature stability, and protein G, the detection of PSA with the sensitivity of 1 108 g/ml, which is the concentration of
strongly suspicious for the prostate cancer, has been achieved.