Modified Pluronic F127 Surface for Bioconjugation and Blocking Nonspecific Adsorption of Microspheres and Biomacromolecules.
Michael W H KirknessChapin S KorosecNancy R FordePublished in: Langmuir : the ACS journal of surfaces and colloids (2018)
Many experiments and applications require the chemical coupling of target molecules to surfaces, during which the elimination of nonspecific interactions presents a difficult challenge. We report on a technologically accessible surface passivation and chemical conjugation method based on an NHS end-labeled F127 Pluronic block copolymer (F127-NHS). To quantify interactions between the F127-NHS surface and magnetic microspheres, we developed a simple assay: the microsphere adhesion by gravity, inversion, then counting, or "MAGIC" assay. To improve blocking of microspheres while maintaining the ability to chemically couple additional molecules, we implemented a pH-dependent two-step chemical modification process for amine microspheres. This process achieves an extremely high level of blocking nonspecific interactions (less than 2% nonspecific adhesion) for a variety of microsphere surface charges and chemical functionalities. We also demonstrate the ability to specifically tether magnetic microspheres to an F127-NHS surface, using single DNA molecules. Using the DNA microspheres, we establish the applicability of the surface for force spectroscopy (stable with an applied load >30 pN) via the massively parallel technique of centrifuge force microscopy. Finally, we demonstrate that the surface can be used in fluorescence studies with a fluorogenic peptide cleavage assay, with high levels of blocking achieved for both the fluorogenic peptide and trypsin. These results suggest applications including, but not limited to, single-molecule force spectroscopy and fluorescence, biosensors, medical implants, and anti-biofouling, which could make use of the F127-NHS surface.
Keyphrases
- single molecule
- molecularly imprinted
- atomic force microscopy
- living cells
- patient safety
- high throughput
- healthcare
- computed tomography
- high resolution
- magnetic resonance imaging
- escherichia coli
- pseudomonas aeruginosa
- mass spectrometry
- magnetic resonance
- transcription factor
- staphylococcus aureus
- quantum dots
- liquid chromatography
- pet ct
- positron emission tomography