Magneto-fluorescent smart nanosystems obtained by one-pot synthesis: from nanostructure to optical response

The development of multifunctional nanoplatforms based on cadmium telluride (CdTe) quantum dots (QDs) and superparamagnetic iron oxide nanoparticles (SPIONs) has attracted considerable interest due to their combined optical and magnetic properties. This study evaluated the influence of composition and polyaniline (PANI) coating on the optical properties of magneto-fluorescent bimodal nanoparticles (BNPs) synthesized by a one-pot route. Optical spectra confirmed the formation of the bimodal systems. QDs exhibited absorption/emission maxima at 535/560 nm (FWHM = 52 nm), while BNPs showed maxima at 530/562, 555/590, 580/617, and 560/580 nm, with FWHM values of 53-61 nm. Moreover, the observed spectral shifts indicated interactions between the nanocomponents. PANI-coated systems exhibited higher fluorescence intensity than uncoated counterparts, even incorporating twice the magnetic fluid volume. These results demonstrate that system composition directly influences the optical properties and highlight PANI coating as a promising strategy for developing magneto-fluorescent nanosystems with enhanced optical performance for nanotechnological applications.