Optically trapped SiO₂@Au particle-dye hybrid-based SERS detection of Hg²⁺ ions

Abstract

The selective ultra-sensitive detection of a very low concentration of analyte in a liquid environment using surface-enhanced Raman spectroscopy (SERS) is a challenging task due to the poor reproducibility of...

Colloidal Manipulation through Plasmonic and Non‐plasmonic Laser‐Assisted Heating

“…[46] For nonspherical nanoparticles (e.g., rod, disc, ellipsoid, etc. ), Equation (7) can be rewritten by incorporating a geometrical correction factor 𝛽 [47] ΔT NS = 𝜎 abs I 4𝜋k m 𝛽R eff (8) where R eff is the radius of a sphere having the same volume as that of the nonspherical nanoparticle. When a homogenously distributed array of nanoparticles participates in the optical process, the system can be treated as one considered in Olber's paradox.…”

“…The early success of OT extended later to other areas of sciences including biological sciences to trap bacteria and viruses, [4] trapping of neutral atoms, [5] etc. The applications of OT are further extended by integrating such techniques with spectroscopic techniques like Raman spectroscopy, [6][7][8] fluorescence spectroscopy, [9][10][11] etc. The prerequisite for a stable OT is that a high optical gradient force should be created via focusing light through a high NA objective to balance the scattering force along the light propagation direction.…”

Microplasma-printed Au-based SERS sensing platform for ultra-sensitive chemical analyte detection

“…20 Besides, it is reported that dielectric materials can localize electric fields by multiple scattering of light. 21 When AuNPs are assembled with dielectric materials, surface plasmon of AuNPs and their electric dipoles are simultaneously generated upon exposure to light. SiO 2 with a low dielectric constant has been recently used to prepare Au/SiO 2 nanocomposites to improve the SERS activities of AuNPs.…”

Highly sensitive and selective SERS substrates with 3D hot spot buildings for rapid mercury ion detection

“…Heavy metal ion pollution has emerged as a major global concern among waste emissions, which significantly threatens ecosystem variety as well as human life and health through cyclic enrichment processes in the environment. [1][2][3] Moreover, Hg 2+ has attracted wide attention owing to its serious damage to the biological system, which could irreversibly destroy the liver, kidneys, heart, and nervous system even at low concentrations. [4][5][6] In the past decades, various analytical techniques, including chromatography, electrochemical methods, atomic absorption spectrometry, atomic emission spectrometry, and fluorescence spectrometry, for detecting and analyzing Hg 2+ have been reported.…”