Immobilization and Stabilization of Biomaterials for Biosensor Applications

Abstract

Biosensors are finding applications in a variety of analytical fields. A biosensor basically consists of a transducer in conjunction with a biologically active molecule that converts a biochemical signal into a quantifiable electric response. The specificity of the biosensor depends on the selection of the biomaterial. Enzymes, antibodies, DNA, receptors, organelles, microorganisms as well as animal and plant cells or tissues have been used as biologic sensing materials. Advances in biochemistry, molecular biology, and immunochemistry are expected to lead to a rapid expansion in the range of biologic recognition elements to be used in the field of biosensors. Biomaterials that are stable and function even in highly acidic, alkaline, hydrophobic, or oxidizing environments as well as stable to high temperature and immune to toxic substrates in the processing stream will play an important role. Techniques for immobilization of the biomaterials have played a significant role in the biosensor field. Immobilization not only brings about the intimate contact of the biologic catalysts with the transducer, but also helps in the stabilization of the biologic system, thus enhancing its operational and storage stability. A number of techniques have been developed in our laboratory for the immobilization of enzymes, multienzyme systems, cells, and enzyme-cell conjugates. Some of these aspects that are of significance in biosensor applications have been highlighted.

Tetraplex formation of surface-immobilized human telomere sequence probed by surface plasmon resonance using single-stranded DNA binding protein

“…complementary nucleotides, in many applications. Analytical and diagnostic methods based on immobilized nucleic acid have gained rapid development and evolved into robust measurement systems, such as biosensors (D'Souza, 2001;Davis and Wilson, 2001) and DNA arrays (Marshall and Hodgson, 1998;Chee et al, 1996). It is key in these applications that the immobilized nucleic acids have to be available to the target molecules so that the desired interactions can take place.…”

“…Such a overhang would be the closest resemblance to the immobilized sequence since it can be regarded as attached at one end to the hosting chromosome. Immobilized nucleic acids have been widely used in many analytical and diagnostic techniques, such as biosensors (D'Souza, 2001;Davis and Wilson, 2001) and DNA arrays (Marshall and Hodgson, 1998;Chee et al, 1996). Formation of secondary structures by immobilized nucleic acids should be avoided for hybridization-based analysis; however it is desired in those applications that rely on the recognition of the structures, such as the G-quadruplex of human telomere .…”

Immobilization of the urease on eggshell membrane and its application in biosensor

“…A large number of techniques and materials have been used for the immobilization of biocatalyst for biosensor application [1][2][3][4][5][6][7][8][9][10][11][12]. The choice of materials and the technique, for the preparation of membranes, has been dictated by the low diffusion resistance of the membrane coupled with its ability to incorporate optimal amount of enzyme per unit area.…”

Biosensor for the determination of phenols based on Cross-Linked Enzyme Crystals (CLEC) of laccase

“…Enzyme stabilization and its storage is an important criterion in the biosensor development (D'souza, 2001;Thakur and Karanth, 2003). Immobilization is commonly used method for the enzyme stabilization and storage, and it can be reused many times.…”