This Small Business Innovation Research (SBIR) Phase 1 project aims to rapidly address the feasibility of using photochemical linkers to immobilize small molecules, synthetic peptides, purified proteins and crude natural extracts onto an electrochemical sensor array. This study is motivated by 1) the need for multiplexed, low cost diagnostics for disease states in which appropriate capture ligands can vary broadly in structure and composition and 2) a need for general attachment methods that are insensitive to structural and compositional differences. Specifically, this project is aimed at diagnostics for drug, food and environmental allergies. We propose to explore the use of perfluorinated phenyl azide (PFPA) chemistry as a reactive and non-selective immobilization strategy for building these diverse arrays. This Phase 1 project aims to identify a single photochemical protocol for preparing arrays in which the immobilized materials retain biological activity. This method will enable the fabrication of highly multiplexed sensor arrays for use in point-of-care diagnostics. The broader impact/commercial potential of this project is to reduce the cost of allergy testing and enable physicians to make evidence-based decisions during a patient's initial office visit (<30 min). Current serological allergy diagnostics available in the market utilize a radioallergosorbent test (RAST) or an enzyme-linked immunosorbent assay (ELISA). These tests can be multiplexed, but require a central laboratory reader, a one week turn-around time and a cost of $15-20 per allergen. The combination of quantitative electrochemical detection with rapid, multiplexed diagnosis of 100+ biomarkers in a single serum sample will provide a significant improvement to existing technologies. If successful, it would be transformative in the clinical diagnosis of allergy diseases, enabling rapid evaluation at the doctor's office in a format that is significantly preferable to laboratory tests, skin-prick testing or food challenges. In addition to the commercial potential of allergy diagnostics, the Phase 1 SBIR project will develop and disseminate a general method for preparing diverse arrays of biologically-active materials on a single support. This new technology would have application in many other fields that affect our health, such as diagnostics for infectious disease and cancer and devices for the detection of food and environmental contaminants