Calixarene: a versatile scaffold for the development of highly sensitive biosensors

Calix[n]arenes, as the ‘third-generation’ host molecules, are cyclic oligomers, featuring a unique three-dimensional structure with a hydrophobic cavity, allowing the interaction with many size-matched guest molecules, and a surface which can be functionalised at both the upper and lower rims with several functional groups to tailor the recognition properties towards a specific class of analytes for various applications. In the last two decades, due to their configuration, unique molecule recognition function and aggregation properties, calixarenes and their derivatives have attracted considerable attention as a new versatile scaffold for highly sensitive detection and site-oriented immobilisation in biosensor development. In this review, the development of sensors featuring calixarene-based transducers tuned for binding many analytes, ranging from simple (i.e., amino acids and neurotransmitters) to complex (i.e., enzymes and antibodies) organic molecules, was described. The rational design, the synthetic strategies fine-tuned to prepare these complex structures and their grafting in surface modification were included.