Since the development of in vitro selection in the 1990s to obtain functional nucleic acids with desired recognition properties, a number of sensing applications have emerged very rapidly. A variety of materials and devices have been successfully developed based on functional nucleic acids for the detection of trace contaminants in water. This chapter highlighted some of the major strengths of this novel approach of combining nucleic acids with nanotechnology: (1) Nucleic acids provide a general class of molecules that can be selected to recognize a variety of diff erent contaminants. (2) In vitro selection can be utilized to tailor the sensitivity and specifi city of the nucleic acid for the contaminant, so as to obtain better sensors. (3) Functional nucleic acids can be readily labeled with fl uorophores and inorganic nanoparticles to obtain sensors with tunable dynamic ranges. (4) The sensors can be assembled into dipstick tests and devices for ease of use, longer shelf life, and regeneration.
In spite of the generality of nucleic acid sensors, there still exist challenges in selecting nucleic acids for certain kinds of analytes, such as anions like perchlorate or nitrate, which are negatively charged and thus are repelled by the negatively charged backbone of nucleic acids. It is important to explore newer selection strategies to overcome these and further expand the repertoire of analytes recognized.
Finally, further development in this fi eld would require development of sensor arrays containing nucleic acids that recognize many contaminants for simultaneous monitoring purposes, similar to the microarray technology commonly used for nucleic acid detection.
Acknowledgment
The authors would like to thank Dr Daryl P. Wernette for assistance with the fi gures. This material is based upon work supported by the U.S. National Science Foundation through the Science and Technology Center of Advanced Materials for the Purifi cation of Water with Systems (WaterCAMPWS, CTS-0120978), the Strategic Environmental Research and Development Program, the U.S. Department of Energy (DE-FG02–08ER64568), and the the U.S. National Institute of Health (ES016865).
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SOCIETAL ISSUES
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449
Savage et al. (eds.), Nanotechnology Applications for Clean Water, 449–451,
© 2009 William Andrew Inc.
Responsible Development of Nanotechnology for Water
Jeremiah S. Duncan, 1 Nora Savage , 2 and Anita Street 2 1 Nanoscale Science and Engineering Center, University of Wisconsin−Madison, Madison WI, USA 2 Office of Research and Development, U.S. Environmental Protection Agency, Washington, DC, USA
Globally, the issues with water quality and quantity are approaching a critical stage. Parts 1–4 of this book present a variety of promising research areas where advances in nanotechnology may provide some much needed technical solutions to a host of water-related problems—drinking water, treatment and reuse, remediation, and detection of pollutants (sensors). As a complement to these sections, Part 5 considers the nontechnical issues related to the use and acceptance of nanotechnology to improve water quality.
In an insightful essay on the relationships between society and the development of nanotechnology, Keller has considered the global successes and failures of nuclear energy and genetically modifi ed foods, arguing that the success of a technology does not depend entirely on its scientifi c merits [ 1 ]. To the contrary, the failure of various technologies may be attributed largely to a host of more complicated and diffi cult-to-predict societal pressures, including public opinion and acceptance, appropriate oversight and governance, demand (or lack thereof) for a solution to a given problem, or failure to study and manage risk at an early enough stage. It is imperative, therefore, to properly consider these nontechnical (i.e., “societal”) issues, lest the potential of the technical solutions be wasted due to lack of foresight and/or understanding.
In other words, there are several questions that ought to be considered with respect to public acceptance of nanotechnology: (1) What is the public’s per- ception (bearing in mind this often has little to do with personal knowledge or level of education)? (2) What is the level of scientifi c literacy (separating science fact from fi ction)? (3) What is and should be the level of public participation in science decision-making? (4) Who owns the technology, what will be developed, for what purpose and for whose benefi t? (5) What is the scientifi c community’s obligation (ethically or morally) to actively engage the public in the pursuit of science when the research is funded with public monies? (6) How should science balance market-driven research agendas with societal needs? And, (7) how and when can the public contribute most meaningfully to encourage
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responsible development of nanotechnology? In this section, these issues and questions are examined to provide some food for thought as the development of nanotechnology—especially in the area of water quality—is developed.
Historically, technologies have been allowed to develop and mature largely without societal infl uence, at least in the early stages of research. In the words of Vannevar Bush, “Scientifi c progress on a broad front results from the free play of free intellects, working on subjects of their own choice, in the manner dictated by their curiosity for exploration of the unknown” [ 2 ]. Although largely successful, as evidenced simply by the historical advances in technology, particularly in the last century, this “technology push” model has meant that ethical, societal (or “social,” depending upon your background), and even environmental considerations have often been overlooked or minimized during the introduction of novel technologies. On the other hand, the “societal pull”
model has been used infrequently but has also been very successful (consider, for example, the space program’s race to the moon in the 1960s, or to a lesser extent AIDS and cancer research). However, as Keller points out, these “push”
and “pull” interactions are, in fact, bidirectional: on the one hand, new technologies infl uence a society’s economic and political structures and often raise issues related to the society’s values and culture. On the other hand, the way society structures its policies and institutions for supporting, regulating, and judging the safety of technologies has a strong infl uence on the pace and direction of their development [ 1 ].
Certainly, the early development of nanotechnology was no exception to the standard model, being more infl uenced by the technology push, though concerns were raised early, for example, by K. Eric Drexler [ 3 ], about the long-term potential for negative consequences. However, a societal pull was begun with the initiation of nanotechnology as a national initiative in the United States, by the passing of the 21st Century Nanotechnology Development Act (Public law 108-153) in 2003, which specifi cally included “ethical, legal, environmental, and other appropriate societal concerns.” Nanotechnology is arguably the fi rst major technological advancement to begin addressing these issues on a large scale at such an early stage in its development. Continuing on this path will be critical as nanotechnology enters, in the words of Mihail Roco, its “second generation” [ 4 ]. In this stage, nanotechnology will go beyond simple material modifi cation to the development of “smart” or active materials, introducing a host of new societal issues. Gorman et al. (Chapter 32), describe a social framework in which these questions may be addressed, and the seemingly confl icting pressures of technological push and societal pull can be resolved by bringing together historically separated groups of people (e.g., technical and social scientists), whereas Rejeski and Michelson (Chapter 33) look at more formal governance structures and policies that may already be acting as obstacles to innovation (i.e., technical push) and adoption of benefi cial technologies (i.e., societal pull).
In Chapter 30, Street et al. further expand on some of the larger societal issues with respect to nanotechnology and water. The need to consider the
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