%0 Journal Article %A Shi, Li %A Carn, Florent %A Boué, François %A Buhler, Eric %T Gold Nanoparticle–Polyelectrolyte Complexes with Tunable Structure Probed by Synchrotron Small-Angle X-ray Scattering: Implications for the Production of Colloidal Crystals-Based Nanophotonic Materials %J ACS applied nano materials %V 6 %N 5 %@ 2574-0970 %C Washington, DC %I ACS Publications %M PUBDB-2023-01197 %P 3990 - 4004 %D 2023 %Z Waiting for fulltext %X Close-packed colloidal crystals of gold nanoparticles (AuNPs) are of great interest in the field of nanophotonics due to their lattice-pattern-dependent optical properties. One challenge resides in producing such crystalline assemblies by a scalable approach involving polydisperse AuNPs obtained by standard synthesis routes and structuring natural molecules in water at room temperature. Electrostatic complexation between functionalized AuNPs and oppositely charged polyelectrolytes (PELs) is a very simple way to create AuNP self-assemblies of different morphologies and compactness. Our work investigates, using synchrotron small-angle X-ray scattering, their structure as a function of concentration, PEL persistence length and ionic strength. By decreasing the radius, R, of the positively charged gold nanoparticles to a few nm (R ≤ 3 nm) and increasing the polyelectrolyte persistence length, L<sub>T</sub>, substituting flexible sodium polystyrenesulfonate for natural semiflexible hyaluronan, we tuned the characteristic ratio L<sub>T</sub>/R up to values of ≥1.85. Such ratios allow the successful formation of a new AuNPs arrangement with a high degree of short-range order at low ionic strength and of crystalline order when interactions are screened by addition of salt. This approach involving commercially available natural water-soluble semiflexible PELs, opens a low-cost and promising way for the one-step production of gold colloidal crystals, which can be of ubiquitous utility in nanophotonics. %F PUB:(DE-HGF)16 %9 Journal Article %U <Go to ISI:>//WOS:000937168200001 %R 10.1021/acsanm.3c00259 %U https://bib-pubdb1.desy.de/record/580329