Peptide-conjugated quantum dots activate neuronal receptors and initiate downstream signaling of neurite growth.

Quantum dots (QDs) could serve as fluorescent scaffolds for effecting specific physiological and pharmacological responses in cells. Here, we conjugate the peptide ligand betaNGF to QD surfaces, and confirm surface modification and single QD nanostructure using AFM. We show that betaNGF-QDs retain bioactivity, activate TrkA receptors, and initiate neuronal differentiation in PC12 cells. Receptor-evoked activity of QD-immobilized ligands has wide-ranging implications for the development of molecular tools and therapeutics targeted at understanding and regulating cell function.