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Articolo in rivista, 2021, ENG, 10.3390/ijms22147465

Additive manufacturing of gold nanostructures using nonlinear photoreduction under controlled ionic diffusion

Di Cianni W.; de la Mata M.; Delgado F.J.; Desiderio G.; Molina S.I.; de Leon A.S.; Giocondo M.

Consiglio Nazionale delle Ricerche, Istituto di Nanotecnologia S.S. Rende, Ponte P. Bucci 33C, Rende, 87036, Consiglio Nazionale delle Ricerche, Istituto di Nanotecnologia S.S. Rende, Ponte P. Bucci 33C, 87036, Rende, Italy;, , Italy; Department of Physics, University of Calabria, Ponte P. Bucci 31C, Rende, 87036, Department of Physics, University of Calabria, Ponte P. Bucci 31C, 87036, Rende, Italy, , Italy; Dpto. Ciencia de los Materiales, I. M. y Q. I., IMEYMAT, Facultad de Ciencias, Universidad de Cádiz, Campus Río San Pedro, s/n, Puerto Real, 11510, Dpto. Ciencia de los Materiales, I. M. y Q. I., IMEYMAT, Facultad de Ciencias, Universidad de Cádiz, Campus Río San Pedro, s/n, 11510, Puerto Real, Spain;, , Spain

Multiphoton photoreduction of photosensitive metallic precursors via direct laser writing (DLW) is a promising technique for the synthesis of metallic structures onto solid substrates at the sub-micron scale. DLW triggered by a two photon absorption process is done using a femtosecond NIR laser (? = 780 nm), tetrachloroauric acid (HAuCl4) as a gold precursor, and isinglass as a natural hydrogel matrix. The presence of a polymeric, transparent matrix avoids unwanted diffusive processes acting as a network for the metallic nanoparticles. After the writing process, a bath in deion-ized water removes the gold precursor ions and eliminates the polymer matrix. Different aspects underlying the growth of the gold nanostructures (AuNSs) are here investigated to achieve full control on the size and density of the AuNSs. Writing parameters (laser power, exposure time, and scanning speed) are optimized to control the patterns and the AuNSs size. The influence of a second bath containing Au to further control the size and density of the AuNSs is also investigated, ob-serving that these AuNSs are composed of individual gold nanoparticles (AuNPs) that grow indi-vidually. A fine-tuning of these parameters leads to an important improvement of the created struc-tures' quality, with a fine control on size and density of AuNSs.

International journal of molecular sciences (Print) 22