User:Melissa Novy/Notebook/CHEM-571/2012/09/05

Objectives

• Prepare serial dilutions of 0.1 M Tris buffer stock solution at the following concentrations: 10 mM, 1 mM, 100 μM, 10 μM.
• Remake Au and BSA stock solutions to check for contamination.
• Resuspend Au/BSA fibers in different concentrations of pH 8 or 10 Tris buffer.

Au/BSA Fibers

• Protocol for Resuspending Au/BSA Fibers
  1. Au/BSA solutions were centrifuged at 3000 rpm, 25°C, for 5 min, such that the fibers formed a pellet at the bottom of the centrifuge tube.
  2. 1 mL of 10 mM pH 8 Tris buffer was added to each pellet and pipetted up and down to resuspend the fibers.
  3. Step two was repeated with Tris buffer at concentrations of 1 mM, 100 μM, and 10 μM on fibers with arbitrary Au/BSA mole ratios.
  4. Steps 2 and 3 were repeated with pH 10 Tris buffer.

• UV-vis spectroscopy was conducted on the resuspended fiber solutions.

UV-Vis Analysis

• Absorbance of AuNP/BSA fibers resuspended in Tris buffer at concentrations of 100 μM, 10 μM, 1 mM, and 10 mM and pH of 8 or 10.

Notes

• Please refer to Keyun Wang's entry for observations on making and centrifuging Au/BSA solutions.
• Please refer to Dhea Patel's entry for volumes and calculations used in remaking the Au/BSA solutions.