"Nanotechnology" has become a key global research initiative. Since the first publication of the concept by Richard Feynman in his well-known 1974 essay "Cargo Cult Science", nanotechnology research has consumed billions of research dollars and has offered unprecedented promises of novel materials/technologies to our daily lives. In technical terms, nanotechnology deals with precision control of structures and arrangements at atomic and molecular scales and propagate these nano-scale molecular orders up to the meso- and macroscopic scales. In practical terms, this precise top-down miniaturization capability has been thought to produce highly efficient information storage and processing devices, novel diagnostics and sensors, as catalysts for high yielding precision chemical reactions, and designers drugs with none to minimal side effects.

From a materials design and synthesis point of view, the key to the scientific and commercial success of this field is the realization of technology to produce highly specific, functional materials, called molecular receptors in an efficient and cost effective manner. These receptors would respond to precision signals for their specific partners called guests. These signals might be electric or optical signals (in the case of information processing) or disease causing bacteria, viruses, or enzymes, toxins etc (in the field of biomedicine). In a daily life analogy, the receptor is a molecular lock that can only be opened by its unique molecular key. Materials scientists have developed a number of novel technologies to prepare such molecular lock-and-key systems.

Nature is abundant with multifunctional materials that show extremely high efficiency and selectivity as well as are intelligent enough to control the function based on the need. Learning from this novel biochemical machinery of the Mother Nature, materials scientists are building such molecular locks. One of such tools is "Molecular Imprinting". Using this technique, researchers are able to mold materials to create molecular-size, precisely shaped pores with functional entities located at predetermined spatial locations.

The process of formation of "molecularly imprinted materials" has borrowed its idea from ancient Greek and Roman empire, but more recently from the work of two greatest scientist: the famous "lock-and-key" analogy of Emil Fischer and "antibody-antigen" interaction theory of Linus Pauling. The material synthesis procedure involves template-induced formation of specific binding sites where the template directs the positioning and orientation of the material's functional components by a self-assembly mechanism. These precise structures are fixed by polymerization process, in a manner similar to the crazy glue fixes two adjoining components. The generic scheme to prepare such precision molecular materials is given below.

Selection	Extraction	Polymerization	Extraction

Molecular Imprinting

Scientists around the world are trying to exploit this class of nanomaterials for a variety of applications. The "proof-of-principle" has been established in a number of cases. For example, for pharmaceutical products, a drug molecule of the same chemical formula and structure but with different 3-D structure (i.e. chiral forms, mirror images, isomers, etc) can have very different property. Some of the examples include the anti-depressant Prozac or the asthma drug, Albutarol for which one isomer is the desired active drug. Development of a cheaper and more efficient way isolate the right 3-D structure from the wrong can make many of these drugs products cheaper, safer, and more potent. By making an imprinted material specific for one isomer, it would become possible to load the manufacturing plant with the mixture at one end and get the desired product at the other end. In the area of biomedical engineering and biomedicine, incorporation of specific characteristics to these materials complementing specific human body functions can lead to designer medicines and devices. For example, by creating a receptor to specifically recognize and bind disease causing bugs in the body or surround an inflammation causing agent offer a new paradigm in healthcare. For example, by specific binding and removal anthrax toxins or smallpox viruses could provide a first line defense against bioterrorism. Furthermore by attracting and shielding certain inflammatory agents to cure rheumatoid arthritis or heal wounds. By making these novel biomaterials/biomedicines (plastic drugs) to perform a highly specific task in a precise manner, the side effects associated with less selective traditional pharmaceutical products can be minimized or even eliminated.

Another potential application of imprinted materials is their use as recognition elements in biosensor/chemical sensor and related devices. A selective (bio)chemical signal resulting from the specific binding between the imprinted receptor and the guest can be transduced into appropriate optical or electrical signals, which can subsequently be put into a readable format. The applications can range from more reliable home-pregnancy and diabetic test kits to detection of chemical/biological warfare agents in combat zone or public place. While biological molecules such as antibodies have dominated this field, the robustness of these synthetic materials (plastic antibodies) offer a number of advantages. They can be resistant to harsh environmental effects, can be durable and avoid the use of host animals to produce. These promises offered by imprinted materials renders them to be viable alternatives to their natural counterparts.

The above examples are just highlights of some of the potential benefits the molecular imprinting technology could bring to the benefits of our lives. However, it is not a done deal yet. The research to develop these materials is still in its early stage and scientists have certain critical issues to resolve before the technology becomes commercially viable. It is not possible to rival Mother Nature during a Ph.D. program time scale or few quarters of business cycle, since the former arrived at her optimum nano-scale precision through millions of years of evolution. Although they have a along way to go, scientists are giving their best shots to make the practical imprinted functional nanomaterials. It should be recalled that couple of years before President Clinton funded multiyear, multibillion-dollar National Nanotechnology Initiative; the term "nanotechnology" was considered a technological Pollyanna or more worse, a pseudoscience!

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