There’s a new polymer out there ready to grab nicotine, the addictive molecule in tobacco, and its kin. Researchers in Poland and the U.S. have designed that polymer so that it can be used to make sensitive and selective chemical sensors to measure nicotine in solutions, and, some day, in gases. The polymer is designed in such way that it can do the opposite and release nicotine, in a slow and controlled fashion, so that it also has applications in nicotine addiction therapy.
Researchers at the Institute of Physical Chemistry of the Polish Academy of Sciences (IPC-PAS) and Wichita State University, led by WÅ‚odzimierz Kutner and Francis D’Souza, placed pincers, much like crab claws, on the polymer that could hold onto nicotine molecules and its analogues.
A press release from IPC-PAS says:
The polymer with pincers for nicotine can be used, among others, in chemosensors devised to analyze nicotine content in tobacco leaves and in biomedical studies to determine nicotine metabolites in patientsâ€™ body fluids. Another potential application is nicotine patches to help quit smoking. The new polymer could be used for prolong and smooth release of nicotine.
At the heart of the nicotine trap is a molecule called a metalloporphyrin derivative. It’s much like the cluster found in red blood cells to hold onto iron. The metalloporphyrin derivative has a ring with a zinc atom as well as the molecular pincers. Nicotine binds to this polymer, so that one part binds to the zinc atom, and another to the pincers.
Beside nicotine, the polymer captures molecules produced during the metabolism of nicotine and other alkaloids that accompany nicotine. Nicotine binds strongly to the polymer, but the binding is reversible. This means that when the polymer is made into a sensor, it can be used repeatedly to detect nicotine and its kind.
When nicotine attaches to the polymer trap, its presence is detected by a piezoelectric resonator. The captured nicotine raises the mass of the film, which causes a decrease in the resonant frequency of the resonator. This decrease in resonant frequency is a cinch to measure and indicates the presence of nicotine.
Right now, the system works in solution, but the researchers are aiming to have it work with greater sensitivity, and in gases.
Source: “Polymer’s hunt for nicotine,”IPC-PAS, 08/04/11
Image released byÂ IPC PAS/Tentaris/ACh.
Rajendrani "Raj" Mukhopadhyay is a science writer and editor who contributes news stories and feature articles on scientific advances to a variety of magazines. Raj holds Ph.D. in biophysics from Johns Hopkins University.