The growing attention to the luminescent nanocarriers is strongly stimulated by their potential application as drug delivery systems and by the necessity to monitor their distribution in cells and tissues. In this communication we report on the synthesis of amphiphilic polypeptides bearing C-terminal phosphorescent label together with preparation of nanoparticles using the polypeptides obtained. The approach suggested is based on a unique and highly technological process where the new phosphorescent Pt-cysteine complex serves as initiator of the ring-opening polymerization of α-amino acid N-carboxyanhydrides to obtain the polypeptides bearing intact the platinum chromophore covalently bound to the polymer chain. It was established that the luminescent label retains unchanged its emission characteristics not only in the polypeptides but also in more complicated nanoaggregates such as the polymer derived amphiphilic block-copolymers and self-assembled nanoparticles. The phosphorescent nanoparticles display no cytotoxicity and hemolytic activity in the tested range of concentrations and easily internalize into living cells that makes possible in vivo cell visualization, including prospective application in time resolved imaging and drug delivery monitoring.Bioimaging based on luminescent microscopy represents one of the most powerful analytical techniques in the life sciences because of its high sensitivity accompanied with simplicity and low cost. This visualization procedure can be carried out using water soluble organic and organometallic dyes, their conjugates with polymers and biomolecules 1-3 , as well as with luminescent nanoobjects 4-7 . The growing attention to the latter approach can be explained by well known practice of application of the nanoparticles to construct advanced drug delivery systems, which also make possible easy visualization of drug distribution in cells and tissues. During the last years, such smart combination of diagnostic and therapeutic properties caused enormous interest in biomedical research area.Nowadays, the nanocarriers intended for a creation of drug delivery systems can be both of inorganic 8 and organic nature 9,10 . Among inorganic nanoparticles applied for bioimaging and drug delivery such systems as dye-doped silica 11 , quantum dots 12 , metal nanoclusters 13 , lanthanide-doped nanoparticles 14 , etc. have got a particular attention. The luminescent properties of organic nanocarriers are usually associated with the native material emission characteristics or are the result of their labeling with emissive moieties. In particular, the materials based on photo-luminescent polyacrylonitrile can be mentioned as an example of label-free organic nanoparticles for bioimaging 15 . However, both the covalent labeling of organic nanoparticles or encapsulation of a dye inside the particles 16,17 are the most common approaches. Encapsulation of dyes in a drug-carrying nanoparticle is usually aimed at synchronous release of drug and dye to signal about drug availability in biological ...