ABSTRACT
This chapter focuses on nucleic acid-based molecular devices and biosensors and their design principles and application in detection and diagnostics. It deals with aptamers and their application in designing biosensors for both detection and diagnostics. The chapter also focuses on application of nucleic acids in imaging. Nucleic acids are biopolymers composed of monomers called nucleotides, consisting of three components: a pentose sugar, a nitrogenous heterocyclic base, and a phosphate group. Thermal as well as chemical stability of nucleic acids plays a crucial role in their application. Molecular devices are based on the predictable interactions between the complementary sequences of deoxyribonucleic acid (DNA) and RNA. G-quadruplex structures are formed in the nucleic acid sequences due to the high guanine content. Like G-quadruplexes, which have a high G-content, i-motif nucleic acids are rich in cytosine content and form four-stranded DNA secondary structures called i-motifs.
