Bidirectional plasmonic coloration with gold nanoparticles by wavelength-switched photoredox reaction

Abstract

We demonstrate bidirectional SPR tuning-based coloration with gold nanoparticles by wavelength-switched photoredox reactions.

Great chiral fluorescence from the optical duality of silver nanostructures enabled by 3D laser printing

“…In this article, we propose and demonstrate photoreduction-based additive laser printing scheme to categorically achieve chiral luminescence with 3D silver nanostructures of optical duality in one go within agarose hydrogel, where the anisotropic factor of the photoluminescence with absolute value can reach up to 0.58 for a single emitter. The silver nanoclusters with the average size amid the mesoscopic scale between isolated metal atom and metallic nanoparticles [26][27][28] can be precisely produced by laser induced photoreduction of silver ions for light emission with its spectrum consistent with previous reports [29][30][31] , whilst the silver nanostructure composed of assembled silver nanoparticles can be simultaneously fabricated to offer a delicate platform for the helicity control in visible wavelength regions with surface plasmon effect 32,33 . As such, the twofold laser printing protocol can readily create nanoemitters with steered luminescence through programmably forming two types of silver nanofeatures at the same time.…”

“…The silver nanoclusters with the average size amid the mesoscopic scale between isolated metal atoms and metallic nanoparticles [26][27][28] can be precisely produced by laser-induced photoreduction of silver ions for light emission with its spectrum consistent with previous reports, [29][30][31] whilst the silver nanostructure composed of assembled silver nanoparticles can be simultaneously fabricated to offer a delicate platform for the helicity control in the visible wavelength region with a surface plasmon effect. 32,33 As such, the twofold laser printing protocol can readily create nanoemitters with steered luminescence through programmably forming two types of silver nanofeatures at the same time. The feasibility of this printing scheme is strongly bolstered by the use of the agarose matrix that renders both pore grids and electron donors for fixing the silver nanoemitters and assisting the silver photoreduction, respectively.…”

Reversible data encryption–decryption using a pH stimuli-responsive hydrogel

“…Upon irradiation of femtosecond laser beam, [Ag(NH3) 2 ] + complex ions near the tight focus can gain energy through two-photon absorption (TPA) process and dissociate to form neutral Ag nanodots attached to the gel network 29 . Remarkably, compared to the photoluminescent dyes employed in common strategies, Ag nanodots are free of the adverse photobleaching effect and exhibit intense scattering from their surface plasmon effect that like other noble metals 30 , making them compelling candidate for optical data storage and reversible data encryption. In this work, through programmatically positioning the focused laser beam, arbitrary plasmonic pattern, which was constituted of discrete silver nanodots, can be generated in the expanded platform.…”

Security-Enhanced 3D Data Encryption Using a Degradable pH-Responsive Hydrogel

“…Under the irradiation of femtosecond laser beam, the [Ag(NH 3 ) 2 ] + complex ions in the vicinity of the tight focus obtained enough energy through a two-photon absorption process and reacted to form Ag nanopatterns attached to the gel network [ 35 ]. Notably, silver nanopatterns reveal strong surface plasmon-scattering effects similarly to noble nanometals [ 36 ], making them a gratifying candidate for optical data storage and data encryption. Resorting to volumetric resolution of the focused laser beam applied in information recording, we achieved 3D data encryption within the hydrogel for the first time.…”