Optimized Au NRs for efficient SERS and SERRS performances with molecular and longitudinal surface plasmon resonance

Single-Molecule Detection-Enabled Plasmonic Ag Nanogap for Unmasking Vibrational Properties in 0D SnO2

“…The collected Raman spectra for concentrations of 10 –14 and 10 –18 M of R6G are shown in Figure b. The characteristic Raman modes of the probe molecule are clearly seen at 1649, 1510, 1360, and 1309 cm –1 for 10 –14 M in Figure b . It is noteworthy that the lowest concentration for the detection of the probe molecule increases up to 10 –18 M in the presence of the Ag nanonet, as depicted in Figure b (inset), and it does not show all the vibrations corresponding to the R6G molecule.…”

“…3b. 29 It is noteworthy that the lowest concentration for the detection of the probe molecule increases up to 10 −18 M in the presence of the Ag nanonet, as depicted in Figure 4b (inset), and it does not show all the vibrations corresponding to the R6G molecule. The observation of such a reduction in the number of all probable Raman peaks of a particular molecule indicates the ultratrace level and indicates single-molecule level detection of R6G molecules with the Ag nanonet.…”

“…Generally, conventional Raman signals are weak, which makes it a challenging task to identify the disorder and surface-related modes in the Raman measurements for SnO 2 nanoparticles (NPs). As a tool to overcome this challenge, surface-enhanced Raman scattering (SERS) is envisaged to reveal the underlying structural information and ultrasensitive trace detection. − In practice, strong enhancement of a Raman signal for an analyte occurs during the SERS measurement due to the presence of plasmonic nanostructures, − where a localized surface plasmon resonance of nanostructures of plasmonic metals such as Ag and Au creates a suitable electromagnetic field (EM) with the light on the metal surface. ,, The EM field becomes highly nonuniform by creating a “hotspot” and results in a highly localized plasmon in unique structures such as sharp edges, nanotips, interparticle nanogaps, or particle–substrate nanogaps. − Kuzume et al, who carried out a SERS study on SnO 2 nanoclusters using the hotspots of shell-isolated nanoparticles (SHINs), also predicted by density functional theory (DFT) calculations the presence of an A 1g mode, but without successful experimental verification . Probably, the electromagnetic field of the specially made shell-isolated nanoparticle-enhanced Raman (SHINER) tag was not adequate for coupling effectively with QDs to produce a signal for the A 1g mode.…”

A Comprehensive Commentary of “Smart Design of High-Performance Surface Enhanced Raman Scattering Substrates”

“…Das et al successfully fabricated Au nanorods with tunable morphology by the seed-mediated growth approach, in which the aspect ratio of the Au NRs can be tuned by controlling the amount of Ag + , CTAB, AA, and seed particles. In addition, Au nanorods presented efficient SERS and SERRS performances under the excitation of 532 nm due to the synergistic effect of LSPR and molecular resonance [18].…”

A Nanoarchitectonic Approach Enables Triple Modal Synergistic Therapies To Enhance Antitumor Effects

“…Several studies have shown that in addition to ablating tumor cells, PTT can further enhance the sensitivity of tumor cells to DOX. , PTT can directly use photothermal agents to transfer near-infrared (NIR) radiation with sublethal or lethal heat to tumors, and it is considered as a promising protocol in situ for cancer treatment. , Among the various photothermal nanomaterials, gold nanorods (GNRs) attract great interest due to their low toxicity, ease to modify, biochemical inertness, and unique longitudinal surface plasmon resonance (LSPR) band in the NIR region. − Owing to two characteristic LSPR bands, GNRs have larger NIR absorption cross sections and higher extinction coefficients for PTT . It should be mentioned that the integration of medical diagnosis (e.g., magnetic resonance imaging [MRI]) with various treatments offers effective therapies with good prognosis, avoids drug resistance, and provides real-time monitoring of treatment progress .…”