The synthesis and host-guest chemistry of new structures based on neutral calix[4]arene supramolecular platforms is investigated. Hosts are substituted to varying degrees with functionalised appendages to form cavities for selectively complexing guests. Functional groups include ureas, amides and nitriles, targeting cations and anions as guest species. The main methods used for transducing complexation events are potentiometry and fluorescence. The various hosts and guests investigated attempt to reflect the versatility and ongoing evolution of state-of- the-art calixarene chemistry within the field of supramolecular chemistry. Throughout the thesis there is particular emphasis on relating host structural changes to changing analytical signal upon complexation with a particular guest. This is the link between the sensing signal and chemistry at a molecular level, the heart of every chemical sensor. The main achievements of this work are a) the development of a urea based chloride selective host with ratiometric fluorescence transduction using pyrenes, b) nitrile based mercury(I1) and silver(1) selective hosts using potentiometric transduction, c) the investigation of an amide-calix[4]arene bromide selective host based on potentiometric transduction, d) the developmet of urea-calix[4]arene ionophores showing potential for improved electrochemical aqueous nitrate sensing and e) a contribution to supramolecular synthesis techniques is made by way of a new semi-preparative liquid chromatographic method for the efficient isolation of pure target compounds.