Microanalytical methods that provide multianalyte profiling information are in high demand. However, the selection of selective probes is sometimes challenging for protein biomarkers. Thus, a reversed-phase array is a reliable analytical system because these probes can better recognize the intrinsic variety of responses compared to single-protein approaches. This chapter also describes the combination of a biorecognition assay and a cheap portable optical biosensing as a powerful solution when an accurate multiple diagnosis is required. As a proof-of-concept, an array-based method was developed as an up-and-coming in vitro diagnostic tool for effectively identifying patients with food allergies. The microanalytical multiplexed assay was supported by compact disc technology (disc, reader, software) as a portable, simple, cost-effective sensing device. Biochip arrays containing a set of immobilized allergens were a feasible solution for detecting 12 food allergies in a single experiment and with a small serum volume. The results were excellent compared to the reference method and other technologies for detecting of specific immunoglobulin E.