# User:Allison K. Alix/Notebook/Thesis Research/2013/09/04

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## Absorbance Measurements of Au@SiO@/DNA (8/29/13)

ε of thiol-DNA= 607500 A=0.553 b=1 cm

A=εbc

c=A/εb

c = 9.10x10^-7M = 0.910uM

[ThT] must be twice what [DNA] is

[DNA] = 0.910μM, so [ThT] must be 1.82μM

Use 150μL of DNA-AuNP solution (10%=15μL)

1.820x10-6M x 165x10-6L solution = 3.003x10-10 moles ThT

(3.003x10-10 moles ThT)/ 15 x 10-6 L = 20.02μM

-Add 15μL of 20.2μM to 150μL thiol-DNA/AuNP solution

NEW Concentrations:

[DNA]= 0.827μM, [ThT] = 1.82μM

1) Prepare 100uL 20uM ThT (use already prepared 5/14/13)

2) React with DNA ten minutes

3) Observe absorbance and fluorescence

## Fluorescence Measurements

The intensity for this is much lower than expected, in comparison to the DNA/ThT samples that were not attached to any particles, BUT much higher than the DNA-ThT that was attached to the nanoparticles only. This might mean that the silica coating is indeed protecting fluorescence form being quenched. The next step is to run measurements on the FCS of different dilutions of this AuNP solution