No abstract

The 2006 U.S. Surgeon General's Report found that there is no safe level of exposure to secondhand smoke (SHS). Many smokers attempt to protect others from exposure to SHS; however, it is difficult to assess effectiveness of these behavior changes. There is a need for personal monitoring devices that provide real-time SHS exposure data; at present, there is no device that measures ambient nicotine levels in real time. The development of such a sensor is the objective of this research.

Conductive composite films comprised of single-walled carbon nanotubes coated with molecularly imprinted poly-4-vinylphenol are produced and characterized using ultraviolet and infrared spectroscopies, confirming the successful molecular imprinting of the film with cotinine. The electrical resistance of the imprinted film changes significantly upon binding cotinine, by more than 30 kΩ, while the unimprinted film in comparison elicits little response. Additionally, once the cotinine template desorbs from the film, the resistance of the imprinted film returns to a value close to the pre-adsorption baseline. Scanning electron microscopy is used to study the morphology of the film compared with the unimprinted control, and gas chromatography quantitatively confirms that the imprinted film selectively detects cotinine while discriminating against the structurally similar alkaloid, nicotine.

No abstract

Atomic force microscopy and nanoindentation have been applied to the study of thin molecularly templated polymer films. The template was chosen to be the readily hydrogen-bonded cotinine molecule and three different polymer hosts, ElvamideV R nylon, Nylon-6, and poly(4-vinylphenol) were compared. The host polymer was shown to affect the nature of the template-host interaction resulting in varying surface morphologies and differences in the nanohardness. These observations were shown to reflect differences in the underlying interaction chemistry, specifically, whether or not the polymer may be imprinted in the film production process.