Integrated photonic biosensors are a highly promising technology platform for biochemical diagnostics. In general, they have demonstrated impressively low detection limits and can offer highly multiplexed operations in real time, but point-of-care solutions require a portable and inexpensive device. In this thesis we investigate a coherently read symmetric Mach-Zehnder interferometer that overcomes its typically associated drawbacks and show that it is an attractive solution for point-of-care devices. Within this work cutting-edge state-of-the-art detection limits were reached in typical bulk sensing and biosensing (with C-reactive protein) performance verification. Finally, targeting a real application scenario, the specific detection of IgG and IgE amoxicillin antibodies was demonstrated applying amoxicillin haptenised PAMAM G2 dendrimers on the sensing area.