The combination of different nanomaterials has been investigated during the past few decades and represents an exciting challenge for the unexpected emerging properties of the resulting nano-hybrids. Spermidine (Spd), a biogenic polyamine, has emerged as a useful functional monomer for the development of carbon quantum dots (CQDs). Herein, an electrostatically stabilized ternary hybrid, constituted of iron oxide-DNA (the core) and spermidine carbon quantum dots (CQDSpds, the shell), was self-assembled and fully characterized. The as-obtained nano-hybrid was tested on HeLa cells to evaluate its biocompatibility as well as cellular uptake. Most importantly, besides being endowed by the magnetic features of the core, it displayed drastically enhanced fluorescence properties in comparison with parent CQDSpds and it is efficiently internalized by HeLa cells. This novel ternary nano-hybrid with multifaceted properties, ranging from fluorescence to superparamagnetism, represents an interesting option for cell tracking.

Department of Bioscience and Biotechnology National Taiwan Ocean University 20224 Keelung Taiwan

Department of Comparative Biomedicine and Food Science Agripolis Campus University of Padua viale dell'Università 16 35020 Legnaro PD Italy

Department of Medicine University of Padua Via Giustiniani 2 35128 Padua Italy

Department of Physical Chemistry Regional Centre of Advanced Technologies and Materials Palacky University Slechtitelu 11 78371 Olomouc Czech Republic

International Polyamines Foundation ONLUS Via del Forte Tiburtino 98 00159 Rome Italy

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