Background and Basic Concepts of Indicator Displacement Assays

Abstract

Taking a step forward from the indicator spacer receptor (ISR) method comprising covalent linkages between receptors and indicators via a spacer, the indicator displacement assay (IDA) offers an innovative and powerful sensing approach for various target analytes in the realm of host-guest chemistry. In this chapter, we have assembled the background and conceptual details in order to give essence to the readers about this innovative sensing approach. The photophysical phenomenon and diverse non-covalent interactions involved in the sensing mechanism have been detailed. We have elucidated the need and urgency to replace the ISR approach with IDA, one having numerous advantages. The evolutionary extension of IDA for enzymatic conversion known as supramolecular tandem assays has also been described in this chapter. We believe that the present introductory chapter will give a better understanding to readers who are new to this field.

Keywords: Analyte, Competitive binding, Dynamic, Detection, Enantiomeric excess, Enzyme, Fluorescence quenching, Guest, Host, Indicator displacement assay, Indicators, Macrocycle, Non-covalent interaction, Receptors, Reversible, Recognition, Sensors, Signal, Substrate, Tandem assays.