User:Allison K. Alix/Notebook/Thesis Research/2013/07/19

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AuNP synthesis procedures

  • We will perform three procedures and observe which produces the desired AuNP diameter (~10nm)

Procedure 1 Taken from User:Allison K. Alix/Notebook/Thesis Research/2013/05/10

1) Stir and heat to boiling 20mL of 1mM HAuCl4

2) Add 2mL 1% sodium citrate

3) Observe a purple to red color change

4) Determine size and concentration of AuNP using UV-Vis

Procedure 2[1]

1) Boil 50mL MilliQ water in a clean beaker

2) Add 0.5 mL of HAuCl4 solution (1% w/v)

  • 1% w/v = (0.01g in 1mL water)

3) Follow with 1.75 mL of sodium citrate solution (1% w/v)

4) Boil for about 10 minutes until solution color changes to bright red

5) Replace water lost to evaporation during boiling

6) If a higher concentration is desired, centrifuge at 14 000 rpm and resuspended in MilliQ water

Procedure 3[2]

1) Bring 100 mL of solution containing 0.01 g of HAuCl4·3H2O to reflux

2) Add 3 mL of 1% sodium citrate solution while stirring

3) Boil solution for another 40 minutes

4) Cool to room temperature

  • Obtain UV-Vis Spectra of all AuNP

Fluorescent changes based on number of G-quadruplexs formed

  • We have already seen that increasing the DNA concentration of an 8-repeat strand results in an increased fluorescence signal. But what happens when we keep concentration of DNA constant and instead decrease the number of repeats to 4, so that only 1 G-quadruplex is formed? Although it was seen that this trend was true using ZnPPIX as a G-quadruplex inducer and fluorescent sensor, it would be beneficial for this research to examine if the same was true for ThT. This would support the idea that the number of G-quadruplexes can be determined based on fluorescent measurements, both bulk and FCS.