Photonics And Biomaterials

The previous chapters have dealt with the applications of interactions of light with biological materials for optical diagnostics and light activated therapy. In

Introduction to Biophotonics, by Paras N. Prasad.

ISBN: 0-471-28770-9 Copyright © 2003 John Wiley & Sons, Inc.

Benefits Biotechnology
Figure 16.1. Interconnection of the various key areas to produce paradigms for new generation information technology.

other words, the focus has been how photonics benefits biotechnology. The other side of the coin is how biomaterials have benefited photonics. In this case, one can exploit interaction of light with naturally occurring biological matter, or materials that may be produced using the same fundamental principles that produce hierarchically built biological assemblies. The latter class of materials is often called bioinspired materials.

Photonics is expected to revolutionize many aspects of data collection, processing, transmission, interpretation, display, and storage. It is the dominant part of information technology for the 21st century and, in its more comprehensive scope, is presented in Figure 16.1.

Availability and future development of new multifunctional materials that can dramatically improve speed and encryption, as well as provide terabit data storage and large-area high-resolution display, are of vital importance for implementation of the full scope of new-generation information technology. Biological systems have provided researchers with a fertile ground with regard to materials enabling new technologies that cover a wide range, from disease therapy, to sensory systems, to computing, and to photonics. In Nature, bio-processes yield structures that are nearly flawless in composition, stereo-specific in structure, flexible, and ultimately biodegradable. Compounds of biological origin can spontaneously organize into complex structures and function as systems possessing long range and hierarchical order. Biological systems also lend themselves to modifications to enhance a specific functionality using both chemical modification and genetic engineering. An important area of application of biomaterial is DNA computing. Although this application has drawn considerable attention, it really does not fall under photonics applications. Photonics applications can utilize a number of diverse groups

PHOTONICS AND BIOMATERIALS 547

TABLE 16.1. Biomaterials for Photonics

Bioderived materials:

Use of naturally occurring biosystems or its chemical or genetic modifications

Bioinspired materials:

Materials such as light-harvesting dendrimers synthesized based on governing principles of biological systems

Biotemplates:

Self-assembly of photonic active structures on a biological template such as viruses

Bioreactors:

Use of bacteria as biosynthesizers to produce photonic polymers of biomaterials for a variety of active and passive functions. Table 16.1 lists biomaterials for photonics.

An example of bioderived material for photonics is green fluorescent protein (GFP) in its wild and mutant forms, which have attracted a great deal of interest as biological fluorescent markers for in vivo imaging and fluorescence energy transfer imaging (FRET) to study protein-protein and DNA-protein interactions. This subject has already been discussed in Chapter 8. Other photonics applications of GFP have also been proposed. Another widely investigated bioderived material for photonics is bacteriorhodopsin (Birge et al., 1999). The main focus has been to utilize its excited-state properties and associated photochemistry for high-density holographic data storage. In addition, a number of other applications have been proposed which are listed in Section 16.2. More recently, native DNA has been proposed as photonic media for optical waveguide and host for laser dyes (Kawabe et al., 2000). Another example is biocolloids which consist of highly structured and complex, discrete biological particles that can be organized into close-packed arrays via surface-directed assembly to form photonics crystals (discussed in Chapter 9). These are some examples of naturally occurring biomaterials for photonics which are described in some detail in Section 16.2.

Bioinspired materials are synthetic materials produced by mimicking natural processes of synthesis of biological materials. A growing field is bio-mimicry with a strong focus on producing multifunctional hierarchical materials and morphologies that mimic Nature. An example of this category is a light-harvesting photonic material that will be presented in Section 16.3.

Biotemplates refer to natural microstructures with appropriate morphologies and surface interactions to serve as templates for creating multiscale and multicomponent photonics materials. The biotemplates can be naturally occurring biomaterials or a chemically modified, bioderived material. Examples are viruses with organized structures of varied morphologies. This topic is discussed in Section 16.4.

Bioreactors refer to the naturally occurring biosynthetic machinery that can be manipulated to produce a family of helical polymers having a wide range of optical properties. An example is a bacterial reactor that can be used to synthesize customized polymeric structures for photonics applications. This topic is discussed in Section 16.5.

0 0

Post a comment