Immobilization of Aptamers on Substrates

This chapter describes different aptamer immobilization chemistries used in the production of aptasensors, providing key examples of the most applied technologies. Aptamer-based biosensors, assays, and diagnostics hold great potential for applications in medical, food safety, and environmental analyses. Typically, the requirements of the desired analytical methods for aptasensor development determine the choice of substrate and chemistry for aptamer immobilization. The chapter categorizes the immobilization based on substrate type: planar or flat gold; solid phase; and nanomaterials. It reviews some recent diagnostic applications in relation to the immobilization method. Several immobilization techniques have been developed in the past years. These include physical adsorption, covalent binding, self-assembly, avidin-biotin immobilization, and hybridization. Strategies for immobilization must be reliable, simple, and must allow the aptamers to retain their biophysical characteristics and binding abilities. The chapter provides an overview of the standard approaches for aptamer immobilization on an array of materials including the relevant advantages and limitations.