Reliable, miniature, multifunctional, real-time optoelectronic sensors can be fabricated by using III nitride materials that have several advantages over the conventional semiconductors. Recent advances in these materials allow integrated optoelectronic devices with tunable spectral characteristics. In addition, optically transparent sapphire substrates and commercially beneficial silicon wafers can be used for the device fabrication. Two concepts of the integrated optoelectronic sensor development are presented in this work. These concepts were investigated by fabrication and testing simulators based on III nitride and Si commercial components. The fabricated devices exhibit multifunctionality expressed by the ability to perform measurements of optical absorption (metallic salts solutions), reflection (interface with commonly used solvents), scattering (alumina powder slurries), and fluorescence (chlorophyll, fluorescein, pyrene, anthracene, and Escherichia coli strains carrying plasmids which encode fluorescent,proteins). These measurements indicate the applicability of the III nitride and Si-based components and their layout according to the described concepts for the development of integrated multifunctional optoelectronic sensors.