A general route towards well-defined magneto- or fluorescent-plasmonic nanohybridsElectronic supplementary information (ESI) available: NMR spectra, magnetic purification, BrCN coupling of 2,2′-dithiobis(ethylamine), Au domain growth on OH- and COOH-functionalized iron oxide NPs, Ag/QD core/satellite hybrids and dot-blot analysis of Ms mAb to ovalbumin conjugated hybrids. See DOI: 10.1039/c3nr04155g

Herein, we present a general route towards defined nanohybrids, comprised of a fluorescent quantum dot (QD) or superparamagnetic iron oxide (Fe 2 O 3 ) nanocrystal core and a tuneable corona of plasmonic gold or silver nanoparticles (NPs), adhered by a cross-linked poly(isoprene)- b -poly(ethylene glycol) diblock copolymer (PI- b -PEG) matrix. To this end, the PEG-terminus of the amphiphilic polymer was acylated with lipoic acid (LA), which, as is known, forms quasi-covalent Au-thiol- or Ag-thiol-bonds. Surprisingly, by variation of the ratio of the different NPs, inverse core/satellite structures bearing QDs or Fe 2 O 3 around a metallic NP core were obtained. Furthermore, gold NPs or even closed gold shells were grown by in situ reductive deposition of Au 3+ ions on Fe 2 O 3 NP seeds. Finally, in order to demonstrate the scope of the method, ternary nanohybrids, composed of QDs, Fe 2 O 3 and Au NPs, were accomplished. All magneto-plasmonic and fluorescent-plasmonic materials were thoroughly characterized by absorption and emission spectroscopy, TEM and TEM-EDX. Antibody conjugation to these novel nanohybrids proved their practical utility in a prototype immunoassay. Well-defined nanohybrids were obtained from quantum dots, iron oxide and gold nanocrystals by controlled assembly with lipoic acid terminated amphiphilic polymers.