Functionalized Au/Ag nanocages as a novel fluorescence and SERS dual probe for sensing

Recent Advances in Nanoparticle Shape and Composition Regulation Based on Galvanic Replacement for Cancer Treatment

“…Since the first report of Au nanocages synthesized from Ag nanocubes, various hollow Au nanoshell structures have been prepared using Ag nanospheres [144][145][146][147][148][149][150][151][152][153][154][155], Ag nanorods [156][157][158][159], Ag nanowires [160], and even Ag islands on two-dimensional surfaces as templates [161].…”

Au and Ag/Au double-shells hollow nanoparticles with improved near infrared surface plasmon and photoluminescence properties

“…Now as per past literatures are concern, most of the cases either pure hollow Au nanoparticles, Au-based bi-layers hollow, and composite hollow nanoparticles show the SPR as well as fluorescence emissions are shifted towards the higher wavelength [2,4,23,40] compared to that of simple Au nanoparticles, which is beneficial for the biomedical applications. In most of the reported studies, hollow bimetallic Ag-Au nanoparticles were synthesized by the galvanic replacement technique of Ag by Au, as a result mostly the shell layer was converted to alloy type [16,41] and therefore those particles showed single absorption and emission peaks at $600 nm and between $700 and 900 nm, respectively depending on the shell thickness. But in this study, the bi-metallic hollow nanoparticles were formed through the successive reduction of each metal precursor step by step in the presence of a strong reducing agent.…”

“…As a consequence, the hollow Au nanoparticles have a higher surface plasmon field generated by photon excitation, and this field is responsible for the higher SPR intensity than solid Au particles [2,[12][13][14]. Hollow Au nanoparticles with larger particle size but lower shell thickness (nano shells) are also able to shift the light absorbance peak position, SPR peak intensity, and photoluminescence peak to the infrared region which is useful for sensor applications in the biomedical field [15,16]. Similar to hollow Au nanoparticles, the noble bimetallic nanoparticles in the forms of alloy, core/shell, and hollow multishells hetero-structures are also equally important because of their similar improved optical properties.…”

Synthesis of Fluorescent Core-Shell Metal Nanohybrids: A Versatile Approach

“…Recently, visualization methods employing AuNPs in optical microscopy, in particular confocal laser microscopy, have been on the rise [24]. In addition to their fluorescence property, AuNPs can enhance Raman scattering for the development of surface enhanced Raman spectroscopy (SERS)-based sensing [25], in which the intense optical frequency field originating from the plasmon resonance of AuNPs can be used for single molecule detection [26]. …”