Tunable photoluminescence properties of [Ru(bpy)2(tatp)]2+ bound to a BSA–SWCNTs film upon incorporation of [Co(phen)3]3+

•Ru(II)–BSA film exhibits the luminescence enhanced by BSA (Kb = 1.9 × 102 M−1).•Ru(II)-based luminescence mediated by BSA is dynamically quenched by Co(III).•SWCNTs promote PET between Ru(II) and Co(III).•PET mediated by BSA–SWCNTs shows detectable photovoltaic response.

Photoluminescence properties of [Ru(bpy)2(tatp)]2+ (bpy = 2,2′-bipyridine and tatp = 1,4,8,9-tetra-aza-triphenylene) bound to a BSA–SWCNTs film (BSA = bovine serum albumin and SWCNTs = single-walled carbon nanotubes) upon incorporation of [Co(phen)3]3+ (phen = 1,10-phenanthroline) are first investigated by means of steady-state and time-resolved fluorescence spectroscopy. The BSA-bound [Ru(bpy)2(tatp)]2+ shows tunable luminescence properties by [Co(phen)3]3+, where an increasing amount of BSA is found to increase the emission intensity of [Ru(bpy)2(tatp)]2+–BSA dyad with binding constant of 1.9 × 102 M−1, and however decrease the luminescence of [Ru(bpy)2(tatp)]2+–BSA–[Co(phen)3]3+ triad with quenching constant of 2.4 × 103 M−1. Moreover, BSA is combined with SWCNTs to construct BSA–SWCNTs bio-nanohybrids, which mediate the photo-induced electron transfer (PET) between [Ru(bpy)2(tatp)]2+ and [Co(phen)3]3+, representing a dynamic luminescence quenching process. On basis of such a PET, [Ru(bpy)2(tatp)]2+ and [Co(phen)3]3+ are assembled on the surfaces of BSA–SWCNTs to fabricate a photoanode and a cathode, respectively, showing detectable photovoltaic response. The present study could provide a versatile platform for the fabrication and evaluation of nanoscale optoelectronic devices.

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