Modular, multifunctional nanoparticle-based bioconjugate for realtime visualization of cellular membrane potential

A method of detecting cellular membrane potential, the method comprising:

• providing a construct comprising a nanoparticle operable as an electron donor;
• a modular peptide attached to the nanoparticle, the peptide comprising a nanoparticle association domain, a motif configured to mediate peptide insertion into a cellular plasma membrane, and at least one attachment point for an electron acceptor positioned at a controlled distance from the nanoparticle;
• and an electron acceptor;
• contacting a cell with the construct;
• and
• detecting visual emission from the construct, wherein the visual emission correlates with cellular membrane potential,
• wherein the modular peptide is selected from the group consisting of SEQ ID No:
• 1, SEQ ID No:
• 2, and SEQ ID No:
• 3.