Bacteriophage Platforms for Amplified Protein Detection Through Visible Plasmon Shifts in Gold Nanocrystal Solutions

Tech ID: 21599 / UC Case 2011-129-0

Background

High sensitivity sensors for specific antigens in solution are in high demand for medical diagnostics and biological assays all over the world. For widespread applicability, these sensors must be low-cost, require minimal need for additional instrumentation, minimize handling of instable proteins such as enzymes, and yet still produce a strong signal in response to a single antigen. To meet all of these requirements, one potential method would be to generate an optical signal or change due to the presence of a particular analyte. However, in order to still have highly sensitive sensors that require minute amounts of antigen, a platform capable of generating amplified responses upon molecular binding must be developed.

In order for protein diagnostics to have worldwide utility, especially in regions of the world with limited equipment and cold storage facilities, methods must be established to rapidly screen for the presence of particular analytes without requiring thermally unstable enzymes or specialized detection apparati, such as microscopes or spectrophotometers. Furthermore, it would be much more efficient and highly advantageous to amplify the signal directly from the sensing agent without extensive synthesis or engineering of new materials. A platform providing optical signal changes as well as the identity of the antigens within a complex mixture would be highly advantageous for protein diagnostics.

Technology Description

Scientists at UC San Diego have developed a new method to engineer unique, solution-based, protein diagnostics with femotomole sensitivities from modified bacteriophage. Specifically, the inventors have engineered the M13 bacteriophage to be a biological platform that can generate an immediate amplified optical change to gold nanoparticle solutions in direct response to molecular recognition binding events. This sensor-based technology is both fast and easy to use and does not require spectroscopic or microscopic analysis, permitting its widespread use in locations with only limited facilities. The sensitivity of this protein sensing technology is currently in the 100-femtomole range. Efforts are underway to enhance sensitivity further by optimizing the functionalization of the phage coat proteins.