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.
Existing microarray platforms utilize attachment chemistries that require specific functional groups to be present in the arrayed materials - typically nucleophiles that are naturally present in proteins. Although highly successful in the context of protein-chip technologies, this approach limits the structures and types of ligands that can be used. Our research innovation is the application of broadly reactive photochemical linkers to attach structurally and compositionally diverse capture ligands to a single support. These capture ligands include small molecule drugs, synthetic peptides, and recombinant purified proteins. A general method for building diverse microarrays finds immediate application in Virogenomics’ development of point-of-care allergy diagnostics. We aim to integrate photochemical functionalization methods with our patent-pending electrochemical device for the sensitive detection of biomolecular analytes in serum samples. This technology permits the preparation of arrays that enable multiplexed, electrochemical biosensors to be used for the rapid, point-of-care diagnosis of allergies. No current array technology has this level of flexibility in design, fabrication and operation. We aim to open up a new set of tools for use in research and FDA approved diagnostics. Our initial market focus is allergy. As many as 11 million Americans are afflicted with serious and sometimes life-threatening allergies to common foods including milk, wheat, peanuts, and shellfish while many more suffer from less-severe but still uncomfortable intolerance or sensitivity to the same items. This problem is increasingly prevalent among American infants (with up to 8% suffering from food allergies) and children (among whom rates of potentially deadly peanut allergies doubled from 1997 to 2002). Food allergies and sensitivities can turn every grocery trip or restaurant meal into a challenge, as consumers search for foods free from these basic, ubiquitous ingredients. Clinical diagnosis of food and airborne allergies can be accomplished by skin-prick tests and food challenges/elimination diets. However there is good correlation between serological testing and in vitro determination of specific IgE linked to allergy diseases. Our initial target product is a simple to use and quantitative electronic diagnostic for determining the level of at least six serum IgE for clinical diagnosis of food and airborne allergies in children. We seek to develop diagnostic products for the quantification of 20+ specific serum biomarkers in a single, rapid point-of-care test. If successful, it would be transformative in the clinical diagnosis of many diseases by enabling rapid evaluation at the doctor’s office. To this goal, we have developed a patent-pending electrode modification and electrochemical detection approach that permits the measurement of serum antibodies with sensitivities omparable to ELISA. In phase I of this project we identified methods for incorporating clinically-useful antigenic materials onto our biosensor platform. In addition to allergy, the proposed biosensor platform would have application in many other fields that affect our health. Such fields of use include diagnostics for autoimmune diseases, infectious disease and cancer as well as detection devices for food or environmental contaminants. This Project Outcomes Report for the General Public is displayed verbatim as submitted by the Principal Investigator (PI) for this award. Any opinions, findings, and conclusions or recommendations expressed in this Report are those of the PI and do not necessarily reflect the views of the National Science Foundation; NSF has not approved or endorsed its content
