Quantum dot clusters as self-assembled antennae with phycocyanine and phycobilisomes as energy acceptors

Phys Chem Chem Phys. 2021 Nov 3;23(42):24505-24517. doi: 10.1039/d1cp03347f.

Abstract

In this study, we investigated an experimental and Monte-Carlo computational characterization of self-assembled antennae built using CdTe colloidal quantum dots (QDs). These clusters provide efficient excitation of phycocyanine (PC) or phycobilisomes (PBSs). PBSs are light-harvesting complexes (LHCs) of cyanobacteria, made of several PC units, organized in disks and rods. Each PC contains three separate cofactors. Therefore, we analyzed variations in multi-donor and multi-acceptor systems. The self-assembled QD clusters were formed mostly by electrostatic interactions, possibly due to the introduction of a positive charge on an originally negatively charged nanoparticle surface. Our results suggest that PC may accept energy from multiple nanoparticles localized at a distance significantly longer than the Förster radius. The excitation transfers between particular nanoparticles with possible delocalization. The maximal energy transfer efficiency was obtained for the PC/PBS : QD ratio from 1 to 20 depending on the QD size. This cannot be fully explained using computational simulations; hence, we discussed the hypothesis and explained the observations. Our self-assembled systems may be considered for possible applications in artificial light-harvesting systems because absorption spectra of QDs are different from the absorption characteristics of PC/PBS. In addition, huge clusters of QDs may effectively increase the optical cross-section of so-created nanohybrids.

MeSH terms

  • Cadmium Compounds / chemistry*
  • Colloids / chemistry
  • Energy Transfer
  • Monte Carlo Method
  • Phycobilisomes / chemistry*
  • Phycocyanin / chemistry*
  • Quantum Dots / chemistry*
  • Tellurium / chemistry*

Substances

  • Cadmium Compounds
  • Colloids
  • Phycobilisomes
  • Phycocyanin
  • Tellurium
  • cadmium telluride