Anion recognition is a cornerstone of supramolecular chemistry, addressing the selective interaction of host molecules with anionic guests through non-covalent forces. Anions are ubiquitous in biological, environmental, and industrial systems, playing critical roles in processes such as enzymatic regulation, cellular signalling, and environmental remediation. However, their diverse geometries, sizes, and solvation properties present significant challenges for selective recognition. Since its inception in the 1960s, driven by the groundbreaking contributions of Lehn, Cram, and Pederson, supramolecular chemistry has proven itself to provide a powerful framework for designing host molecules that exploit hydrogen bonding, halogen bonding, ion-dipole interactions, and electrostatic forces to bind specific anions. These interactions are often fine-tuned using macrocyclic, cage-like, or anion-π receptor architectures, allowing for enhanced selectivity and binding strength. Advances in supramolecular design have enabled the detection of environmentally hazardous anions (e.g., nitrate and phosphate) and biologically relevant anions (e.g., chloride, sulfate, and ATP), providing tools for sensing, diagnostics, and pollutant capture. Moreover, the principles of anion recognition extend to functional applications such as anion transport across lipid bilayers, a process critical for mimicking ion channels and addressing chloride-related diseases like cystic fibrosis. Supramolecular systems that integrate anion recognition and transport highlight the transformative potential of this field in solving contemporary challenges in medicine, environmental science, and materials development. This thesis titled “The Design and Synthesis of a new Biomimetic code: Squaratides” aims to introduce a new class of peptidomimetic receptors – a hybrid mix of squaramides and peptides that we call “squaratides”. This new building block enables the creation of a library of modified amino acid-based biopolymers that can be tailored for improved hydrogen-bond donor and acceptor behaviour, producing a diversity of anion receptor subtypes with readily engineerable cavity size, lipophilicity and charge. The thesis opens with a literature review (Chapter 1) documenting the historical perspective on the supramolecular chemistry of anion recognition, addressing the importance and challenges faced with anion recognition and anion receptors, followed by the unique structural features of macrocyclic receptors, such as their well-defined structures and pre-organised binding sites, that contribute to their exceptional anion-binding and transport capabilities. Chapter 2 details the design of a new peptidomimetic scaffold that incorporates squaramides into the peptide backbone, utilising all the advantages that squaramides offer including rigidity, aromaticity and strong specific anion binding. This new building block enables the creation of a library of modified amino acid-based biopolymers that can be tailored for improved hydrogen-bond donor and acceptor behaviour. With this new class of receptors at hand, we use a combination of experimental techniques to characterise the solid and solution state behaviour of the squaratides as well as their ability to discriminate specific anions through preferential binding interactions. Chapter 3 builds upon the data and insights presented in the previous chapter whereby we optimise the synthetic pathway of our previously described squaratides as a means to synthesise what we call 2nd generation squaratides. Developed through a solid support using SPPS, this synthetic approach grants us the flexibility in designing longer squaratide chains as well as larger macrocyclic squaratides with various cavity sizes allowing us to utilize this approach for carrying work out on exploring squaratides as antimicrobials. we have generated a structurally diverse library of receptor subtypes. These synthetic constructs are designed to replicate the membrane-targeting activity and selectivity of natural antimicrobial peptides, while offering enhanced stability and tunability. This work highlights the potential of cyclic and modular frameworks as next-generation platforms for addressing the growing challenge of antimicrobial resistance. Chapter 4 utilises the new solid phase synthesis approach to squaratides mentioned in Chapter 3, where we set out to synthesise asymmetric squaratides and a fluorinated squaratide as well as taking advantage of the functionalisation capability of these receptors in order to synthesise a family of functionalised squaratides by incorporating anion binding motifs onto the side chains of the squaratide backbones as a means to further enhance anion recognition as well expanding the application range of squaratides by studying them as potential anion transporters. Chapter 5 reveals the development and study of a novel fluorescent based squaratide. By integrating a napthalimide based fluorescent amino acid into the peptidomimetic backbone, we give rise to the first fluorescent squaratide; Sq-2-Lys-Naph, which functions as a self-reporting anion sensor, providing real-time optical feedback on fluoride binding and displacement. We envisage that this design principle can be expanded to engineer new fluorescent peptidomimetics with tailored selectivity and tuneable optical responses.