Author(s): Utembe, W.

Source: In Some Key Topics in Chemistry and Biochemistry for Biotechnologists (pp. 177-190). CRC Press

Abstract: Chirality, which arises from lack of symmetry, results in pairs of enantiomers that possess similar physico-chemical properties but different chiroptical properties. The differences in chiroptical properties of enantiomers can be assessed using methods that are based on circular dichroism, polarimetry and optical rotary dispersion. Chirality is not limited to organic molecules but also exists in inorganic compounds and nanomaterials (NMs) on which chirality can be bestowed by the adsorption of chiral molecules, asymmetric arrangements of achiral ligands, or by crystal design that exposes unequal stepped surface structures. Chirality in NMs can be stronger than those observed in chiral molecules, and biochemical receptors can differentiate between enantiomeric pairs of chiral NMs. As chirality affects the biological properties of some NMs and not of others, investigations of the effects of chirality of NMs are needed on a case-by-case basis. Indeed, although most NMs are achiral, it is very important to take into account the effects of chirality whenever it occurs, so that biochemical studies may have to be conducted on each enantiomer, the racemate and any relevant enantiomeric ratios of the NMs. This chapter discusses occurrence of chirality in NMs, methods of analysis, and the implications of chirality on biochemical systems.