Reversible regulation of esterase activity via host–guest molecular recognition at the nanoparticle surface

Precise and controlled regulation of enzymes is an important aspect to understand their fundamental complex biological molecular mechanism. While many synthetic receptors were developed to inhibit enzymatic activity, they lack reversible control over their function. Herein, we present an engineered nanoparticle (NP) surface that synergistically combines host–guest assembly with protein surface targeting to reversibly control enzyme activity. We demonstrate the effective inhibition of anionic esterase enzyme activity upon electrostatic binding to dimethyl-benzyl ammonium terminated positively charged gold NPs. The NP surface upon threading by non-covalent host–guest interactions with CB[7] moiety has enabled the reactivation of enzyme catalysis. This reactivation has been further reversed by disrupting NP–CB[7] complex by employing a competitive orthogonal guest, hence leading to the controlled reversibility of enzyme activity. Tuning of NP surfaces by different supramolecular interactions and concomitant protein recognition on the NP surface can thus be emphasized as a significant tool for biotechnology applications.