Journal
LANGMUIR
Volume 21, Issue 25, Pages 11568-11573Publisher
AMER CHEMICAL SOC
DOI: 10.1021/la0519960
Keywords
-
Funding
- NIBIB NIH HHS [5R01EB000720] Funding Source: Medline
Ask authors/readers for more resources
In this paper, we describe a new method of measuring alkanethiol monolayer formation on a gold surface. A gold-coated millimeter-sized rectangular-shaped lead zirconate, titanate (PZT) cantilever of dimensions 3.5 x 2 x 0.05 mm, previously shown to detect a picogram level of mass change, was used to measure the adsorption kinetics of 1-hexadecanethiol in ethanol over six orders of concentration range (1 nM to 10 mM) in real time. The flexural mode of cantilever vibration, 45.5 0.01 kHz, was monitored during the self-assembly. The total resonant frequency change obtained for the 1 nM, 10 nM, 100 nM, I,uM, 4 mM, 8 mM, and 10 mM thiol concentrations were 116 +/- 2 (n = 2), 225 m = 1), 270 +/- 10 (n = 2), 440 +/- 10 (n = 2), 900 +/- 10 (n = 2), 900 +/- 10 (n = 2), and 900 +/- 10 (n = 2) Hz, respectively. These results compare favorably to literature results in that the rate of the monolayer formation is concentrationdependent and the exponential change during adsorption follows the reversible first-orderLangmuir kinetic model. The rate constants of adsorption and desorption were 0.061 M-1 s(-1) and 3.61 x 10(-4) s(-1), respectively. The significance of the results is that millimeter-sized PZT cantilevers can be used in real-time for characterizing self-assembly of monolayer formation at nanomolar concentration levels. In addition, at 1 nM, the adsorption was found not to be diffusion limited.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available