Natural fiber exoskeletons of insects and arthropods. In shells and exoskeletons, the chitin fibers contribute to their hierarchical structure. In nature, pure chitin (100% acetylation) does not exist. It instead exists as a copolymer with chitin's deacetylated derivative, chitosan. When the acetylized composition of the copolymer is over 50% acetylated it is chitin. This copolymer of chitin and chitosan is a random or block copolymer. Chitosan is a deacetylated derivative of chitin. When the acetylized composition of the copolymer is below 50% it is chitosan. Chitosan is a semicrystalline “polymer of β-(1-4)-2-amino-2-deoxy-D-glucose”. One difference between chitin and chitosan is that chitosan is
Fluorescent glucose biosensor addition to the fluorophore(s), a molecule that confers glucose specificity, in general, a protein. A variety of proteins have been used for this purpose, often with different labs concentrating on one particular protein. The first glucose biosensor reported in the literature was made in 1982 by Schultz’group using a competition assay between glucose and a labelled glucose polymer for the binding site of Concanavalin A entrapped in a hollow dialysis fibre. As a result, Con A was widely used in subsequent sensors in several labs, however Con A suffers from the downside of high toxicity and low reversibility. As a