Molecular devices designed to assess and manipulate biologically relevant conditions with required accuracy and precision play an essential role in life sciences research. Incorporating allosteric regulation mechanism is an attractive strategy toward more efficient artificial sensing and switching systems. Herein, we report on a new principle of regulating switching parameters of a DNA-based molecular device based on allosteric interaction between spatially separated hairpin stem and a tetraplexed fragment (i.e., i-motif). We characterized thermodynamic and kinetic effects arising from interaction between functional domains of the device and demonstrated the potential of applying the allosteric control principle for rational design of senso...