DNA sequence-induced modulation of bimetallic surface plasmons in optical fibers for sub-ppq (parts-per-quadrillion) detection of mercury ions in water

Abstract

Hg2+ detection sensitivity modulated by ssDNA sequence based binary numbers in bimetal-plasmonic optical fiber sensor that triggers ssDNA chemo-mechanical folding.

Fluorescence Based on Surface Plasmon Coupled Emission for Ultrahigh Sensitivity Immunoassay of Cardiac Troponin I

“…The Cr layer acts as an adhesive layer for coating the Ag layer on a glass substrate [ 31 ]. The 2 nm-thick Au layer enables the thiol-linking to be used for immobilizing the capture probes, while acting as anti-oxidization protective layer for the inner Ag layer [ 26 , 32 ]. Use of the Ag layer as the prime metallic film for surface plasmon is supported by its higher quality factor, indicating a greater number of dye molecules coupled for more highly effective SPCE than in a case of an Au layer at visible wavelengths [ 26 , 32 , 33 , 34 , 35 , 36 ].…”

“…Figure 1d shows the spectra of fluorescence from D-Ab@Alexa 488 in dried condition, The Cr layer acts as an adhesive layer for coating the Ag layer on a glass substrate [31]. The 2 nm-thick Au layer enables the thiol-linking to be used for immobilizing the capture probes, while acting as anti-oxidization protective layer for the inner Ag layer [26,32].…”

“…Use of the Ag layer as the prime metallic film for surface plasmon is supported by its higher quality factor, indicating a greater number of dye molecules coupled for more highly effective SPCE than in a case of an Au layer at visible wavelengths [26,[32][33][34][35][36].…”

Plasmonic Optical Biosensors for Detecting C-Reactive Protein: A Review

“…SPR can occur at the interface between metal and dielectric media that include target biomolecules (e.g., CRPs), via a coherent coupling of surface plasmons with external photons. The surface parallel component of photon momenta offered by a high index prism [ 19 , 29 , 42 , 43 , 44 , 45 , 46 , 47 , 72 , 74 ] or a fiber core [ 48 , 55 , 75 , 76 , 77 , 78 , 79 ], can match those of surface plasmons, generating a coherently coupled state, i.e., the surface plasmon polaritons. The momenta required for such matching are subject, with great sensitivity, to a change in an effective refractive index of dielectric media near a metal film, due to the Debye screening effects, thus overriding the resonance conditions [ 61 , 80 , 81 ].…”

“…Amid the methodologies mentioned above, optical plasmonic sensors have attracted much attention for detecting biomarker molecules without labels such as fluorescent tags, due to a number of advantages [ 52 , 53 , 54 , 55 , 56 , 57 , 58 , 59 ]. They include the high sensitivity without contaminating target biomolecules, the capability of multiplexed assay, a small amount of an analyte sample required, the relative immunity to external factors (ambient temperature variation/external electric disturbance), and the observability of time-dependent kinetic behavior of bio-molecular interactions [ 3 , 60 ].…”