Difference between revisions of "User:Moira M. Esson/Notebook/CHEM-571/2013/11/20"

Objectives

1. Re-prepare BSA-AuNP solutions that were originally prepared on 11/19/2013 because these solutions did not form fibers
2. Analyze invertase-AuNP solutions prepared on 11/19/2013 using UV/vis and AA spectroscopy.

UV/vis spectroscopy

• The general protocol for analyzing Au-NP solutions via UV/vis spectroscopy described on 11/06/2013 was followed.

Figure 1. Corrected Absorbance Spectra of Invertase Au-NP solutions

AA spectroscopy

General Protocol

1. Transfer 3mL of sample from test tubes into a 10mL falcon tube.
2. Centrifuge 3mL protein-AuNP solutions for 30 minutes at 4000rpm. Be sure that the centrifuge is balanced.
3. Prepare 5 standard Au solutions (10μg/mL, 20μg/mL, 30μg/mL, 40μg/mL, 50μg/mL) following protocol described on 09/10/2013.
4. Run samples on AA.

Table 1. Standard Au Solution preparation from 1000μg/mL AA Au gold standard solution

Figure 2. Calibration Curve of Gold Standards

Figure 3. Atomic Absorption spectra of Invertase AuNP solutions

• The strange shape of this spectra will be investigated. This may be related to the varying color of the solutions. The solutions are colored, then appear colorless, then are again colored (see images below)

Figure 4. Absorbance vs. Concentration plot of the Invertase:AuNP solutions

Notes

• All BSA solutions prepared 11/19/2013 did not form fibers. This did not coincide with all other lab groups data. It is suspected that the BSA stock solution was prepared inaccurately. New nano-particles will be prepared.

Figure 5. BSA-AuNP solutions that did not form fibers.

Figure 6. Invertase-AuNP solutions that did form fibers(ratio 30:1 on the left and 50:1 on right).

• In comparison to previously prepared fibers, these fibers are much smaller and less string-like in appearance.