The article proposed dual wavelength silicon based photo detector with multi-layer structure, was fabricated and characterized with dual wavelength enhanced operating. We proposed the dual wavelength response of the silicon based bio-photo-detector. It can be enhanced by introducing thin porous silicon layer as the base region of transistor. The device process of manufacture is suitable in design of visible-light sensitive bio-photo-detectors. The experimental results showed that the dual wavelength responses in the developed devices were enhanced as compared to the silicon-based homo-junction photo-detectors in optical parameters, which indicated that the developed bio-photo-detector showed potential for practical silicon based biomedical device and system applications.