Tuning and Activation of Titania Anatase Core-Shell Particles

Applying forces to investigate the mechanics of biological substrates has become increasingly pertinent while exploring the use of biomolecules as nanomaterials. Typically, micrometer-sized polystyrene beads treated with biologically relevant molecules are used to bind to these biological substrates in question to determine key force barriers as per their specific physical integrity. In order to explore such forces a device known as optical tweezers is used alongside an optical microscope. The optical tweezers use an emitted laser of known frequency and power in order to hold these polystyrene beads in place and furthermore move them, stretching the biology linked between the particle and the slide surface. A well-known and common candidate for stretching is ds-DNA. As interest in nanomaterials has increased, durability of these nanomaterials has become a hot topic among the biophysics community. With these polystyrene beads the measurable trap strength at maximum can see numbers in the area of 250 pN1, which is simply not large enough to explore other more durable materials, namely amyloid fibrils. Titania Anatase core-shell particles have extreme potential in the area of increasing trap strength and consequently the limit of force measurements. Our data shows that through tuning the particles to specific size and shape distribution, the trap stiffness has increased as much as 3.5 times from the polystyrene standard. Even with this data the magnitude of 1-2 nN would not be out of the question2. Specifically, the tunability of these titania core-shell particles makes them intriguing for research purposes as finding a curve for heating time (index of refraction) to trap strength would allow for the creation of optimal core-shell particles and consequently allow for research into tougher materials such as the proteinaceous amyloid fibrils.