The present invention provides Modular Molecular Clasps and methods of using these Modular Molecular Clasps in a wide range of applications in the health care industry, e.g., in therapy, in clinical diagnostics, in in vivo imaging or in drug discovery. The Modular Molecular Clasps of the present invention also have industrial and environmental applications, e.g., in environmental diagnostics, industrial diagnostics, food safety, toxicology, catalysis of reactions or high-throughput screening; as well as applications in the agricultural industry and in basic research. Methods of designing the Modular Molecular Clasps, as well as arrays and biosensors comprising these Modular Molecular Clasps are also provided.