Monitoring of Enzymatic Proteolysis Using Self-Assembled Quantum Dot-Protein Substrate Sensors

Figure 1

(a) Schematic depiction of the QD-protein bioconjugates and the change in PL signal following interactions with target protease. Self-assembly of Cy3-labeled proteins on the QDs induces efficient FRET between the QD and dye. Only one protein is shown for brevity, not to scale. Added protease cleaves/digests the protein and changes the FRET signature. (b) Normalized absorption and emission spectra for Cy3-labeled MyG (Cy3 QY = 0.20, 𝜀≅150,000M⁻¹cm⁻¹, 𝜆_exc=555nm, 𝜆_em=570nm) and 530 nm emitting QDs (QY≅0.20, QD-Cy3 𝑅₀≅52.5Å). Note: the QD absorbance is not normalized.

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