Potential of an AgInS ₂ quantum dot/albumin nanoparticle system for photodynamic therapy

Subject of study. This study investigates free AgInS 2 and AgInS 2 /ZnS quantum dots and quantum dots encapsulated in albumin nanoparticles (ANPs). Aim of study. The aim of this study is to determine and compare the fluorescence properties and reactive oxygen species-generation abilities of free quantum dots and quantum dots encapsulated in ANPs for their use as photosensitizers (PSs) in photodynamic therapy (PDT). Method. The quantum dots were synthesized using a hydrothermal method, and the ANPs were obtained by the desolvation method. The quantum dots were encapsulated into the ANPs by co-incubation in aqueous solution. The efficiency of superoxide generation was evaluated using a selective chemical sensor. Main results. Growing a ZnS shell on AgInS 2 quantum dots increased both their fluorescence quantum yield and efficiency of superoxide generation. The encapsulation efficiencies of AgInS 2 and AgInS 2 /ZnS quantum dots in ANPs were 60% and 20%, respectively, and they were accompanied by a hypsochromic shift in the fluorescence spectra of the quantum dots. Encapsulation of the quantum dots in ANPs led to a decrease in superoxide-generation efficiency compared with free quantum dots; however, this reduction may be compensated for by their greater stability in biological systems. Practical significance. The findings of this study on the photophysical properties of AgInS 2 quantum dots demonstrate the high potential of nanoplatforms based on quantum dots and ANPs as PSs for PDT.