Measuring the Content of a Single Liposome through Electrocatalytic Nanoimpact "Titrations"

We show the electrochemical determination of attomole glutathione contents within single individual liposomes at low overpotentials through mediated electron transfer by using copper (II) as a catalyst for the oxidation of liposomal glutathione. A “titration‐like” behaviour of individual liposomes was observed when impacting with the electrode to quantify the content within single liposomes. The nanoimpacts “titration” strategy allows the characterisation of nanoparticles containing redox‐inactive molecules at the single‐nanoparticle level. High‐impact nanoimpacts: The electrochemical determination of attomole glutathione contents within single individual liposomes at low overpotentials through mediated electron transfer is demonstrated by using copper (II) as a catalyst for the oxidation of liposomal glutathione. The novel nanoimpacts “titration” strategy allows the characterization of nanoparticles containing redox‐inactive molecules at the single‐nanoparticle level.