Probing the Fluorescence Behavior of DNA-Stabilized Silver Nanoclusters in the Presence of Biomolecules

DNA-stabilized silver nanoclusters (DNA-AgNCs) have promising properties for biosensing and bioimaging applications. However, in order to enhance the applicability in these fields, a detailed understanding of the interactions that occur between DNA-AgNCs and other biomolecules is essential. In this work, the spectroscopic properties of red-emitting DNA-AgNCs have been investigated in the presence of three biomolecules, namely lysozyme, bovine serum albumin and ss-DNA, which have been selected in order to have either a different biological nature (two proteins and one nucleic acid) or different net charge at physiological pH (one positive and two negative). The systematic characterization of the steady-state absorption and emission spectra, combined with time-resolved fluorescence and anisotropy decay measurements, of DNA-AgNCs in the presence of each biomolecule, allowed to establish the nature of the interactions that affect the photophysical properties of the DNA-AgNCs.