Monitoring interfacial bioelectrochemistry using a FRET switch.
Generation of functionally active biomolecular monolayers is important in both analytical science and biophysical analyses. Our ability to monitor the redox-active state of immobilized proteins or enzymes at a molecular level, from which stochastic and surface-induced variations would be apparent, is impeded by comparatively slow electron-transfer kinetics and associated signal:noise difficulties. We demonstrate herein that by covalently tethering an appropriate dye to the copper protein azurin a highly oxidation-state-sensitive FRET process can be established which enables redox switching to be optically monitored at protein levels down to the zeptomolar limit. The surface-potential-induced cycling of emission enables the redox potential of clusters of a few hundred molecules to be determined.
Davis
J J
JJ
Central Research Laboratory, Mansfield Road, Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QR, United Kingdom.
Burgess
H
H
Zauner
G
G
Kuznetsova
S
S
Salverda
J
J
Aartsma
T
T
Canters
G W
GW
D001400:Azurin / Q000737:chemistry*; D001703:Biophysics / Q000379:methods*; D002627:Chemistry, Physical / Q000379:methods*; D004396:Coloring Agents / Q000494:pharmacology; D003300:Copper / Q000737:chemistry*; D004563:Electrochemistry / Q000379:methods*; D004566:Electrodes; D004583:Electrons; D031541:Fluorescence Resonance Energy Transfer / Q000379:methods*; D007700:Kinetics; D008956:Models, Chemical; D008968:Molecular Conformation; D010084:Oxidation-Reduction; D017434:Protein Structure, Tertiary; D013499:Surface Properties
D004396:Coloring Agents; D001400:Azurin; D003300:Copper