DNA/RNA Aptamers for Illicit Drug Molecules

Abstract

In this chapter, the use of synthetic DNA/RNA aptamers is discussed as alternatives to their biological equivalents—antibodies—in the context of illicit drug detection. Antibodies are at the cornerstone of molecular recognition in diagnostic devices used for drug detection, but they have a number of drawbacks that make synthetic alternatives attractive. Aptamers can be produced at a fraction of the cost of antibodies and over far quicker timescales (months rather than years). They also show little batch-to-batch variability and have much longer shelf lives. Whilst there are a number of applications and devices in which aptamers are used to detect large-molecule biopharmaceuticals, there is a paucity of aptamers that have been discovered with affinities for small drug molecules, which are typically representative of illicit drugs. This chapter proposes that this may be due to flaws in both the aptamer selection process for small molecules and the methods used to calculate their target affinity. Modifications to these aspects could lead to a greater uptake of aptamers with the consequential benefits of improvements in illicit drug detection.