Luminescent quantum dots (QDs) exhibit size- and composition-tunable photophysical properties that are not shared by their bulk parent materials or at the molecular scale. They have attracted considerable interest further motivated by several potential applications. A particular interest has centered on exploiting the ability of QDs to engage in both fluorescence resonance energy transfer (FRET) and charge transfer (CT) interactions with proximal fluorophores and redox active molecules/complexes, respectively. In this review, we highlight how the QD's optical and spectroscopic properties can be controlled via FRET and/or CT interactions. We first show that QDs provide a unique platform for controlling both modes of interactions. We then provide representative examples in biology which include developing sensing assemblies that report on properties such as pH changes, enzymatic activity and ligand receptor binding. Implications in electronic devices focus on light emitting devices and photovoltaic cells, where we discuss device architecture, control over carrier injection, carrier mobility, and exciton recombination. (C) 2015 Elsevier Ltd. All rights reserved.