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Technology

This invention introduces a novel synthetic recognition scheme for macromolecules that, unlike natural systems, is not constrained by cost or production scale and can withstand long-term storage. The synthetic recognizer is comprised of a single-walled carbon nanotube (SWCNT) with adsorbed heteropolymer on its surface. This is achieved through the dialysis of a surfactant-SWCNT suspension in the presence of the heteropolymer for wrapping exchange. The hydrophobic segments of the polymer are adsorbed onto the hydrophobic surface of the SWCNT. This pushes the hydrophilic portions into the surrounding solution, forming a corona phase that is unique to the configuration of the heteropolymer and capable of recognizing target analytes. Previous work has demonstrated that these sensors are capable of recognizing small molecules, such as riboflavin, L-thyroxine, and small neurotransmitters, and a recent screen has suggested that they are also capable of recognizing macromolecules. Of 14 protein analytes and 20 distinct SWCNT corona phases screened, a particular corona phase molecular recognition (CoPhMoRe) scheme using SWCNT suspended in a phospholipid-PEG construct was discovered to be capable of recognizing fibrinogen, a blood plasma macromolecule protein. Screening for binding was accomplished through detecting spectral changes corresponding to analyte binding, such as fluorescent intensity and emission wavelength modulation, both of which are fast and easy to perform. Atomic force microscopy, quartz crystal microbalance with dissipation measurements, and kinetic measurements all suggest that fibrinogen physically binds to the CoPhMoRe phase owing to a unique 3D interaction between the conformation of the corona phase and the fibrinogen molecule. Since even such a small screen was capable of identifying the strong binding specificity of a particular corona phase to a macromolecule, future screens will likely identify many other such interactions.