Preparation of high-efficiency near-infrared aggregation-induced emission nanoparticles based on FRET and their use in bio-imaging

Abstract

Recently, the development of fluorescent probes has contributed to significant advances in cell biology and medical diagnostic imaging. In this work, we use biocompatible bovine hemoglobin (BHb) molecules to co-coat aggregation-induced emission (AIE) molecules amino tetraphenylethylene (TPE-NH2) and near-infrared emission molecules 2-(4-aminophenyl)-3-(4-(4-(diphenylamino)styryl)phenyl) fumaronitrile (TPAADFN), to get TPE-NH2/TPAADFN@BHb nanoparticles. Due to the fluorescence resonance energy transfer (FRET) between the two fluorescent molecules, the prepared fluorescent nanoparticles have high fluorescence quantum efficiency. The prepared TPE-NH2/TPAADFN@BHb nanoparticles also have large Stokes shift, which helps to avoid the cross-talk between the absorption and emission of the particles themselves. This is beneficial to avoid the self-absorption of biological tissues and obtain very high detection sensitivity. Furthermore, due to the good biocompatibility of BHb, TPE-NH2/TPAADFN@BHb nanoparticles have good mono-dispersity, low toxicity and high brightness, which is very propitious in the application of bio-imaging.