Present results demonstrate that the redox potential and hence the chemical reactivity of a solute dissolved in a polymer-surfactant supramolecular assembly, considered as a nanoreactor, can be tuned substantially by changing the composition of the supramolecular assembly. It is understood from detailed study that, on changing the polymer-surfactant composition of the supramolecular assembly, the probe undergoes a change in its location in these nanoreactors and accordingly its physical and chemical properties can be modulated.