Silver-Nanoparticle-Embedded Porous Silicon Disks Enabled SERS Signal Amplification for Selective Glutathione Detection

Abstract

As the major redox couple and nonprotein thiol source in human tissues, the level of glutathione (GSH) has been a concern for its relation with many diseases. However, the similar physical and chemical properties of interference molecules such as cysteine (Cys) and homocysteine (Hcy) make discriminative detection of GSH in complex biological fluids challenging. Here we report a novel surface-enhanced Raman scattering (SERS) platform, based on silver-nanoparticleembedded porous silicon disks (PSDs/Ag) substrates for highly sensitive and selective detection of GSH in biofluids. Silver nanoparticles (AgNPs) were reductively synthesized and aggregated directly into pores of PSDs, achieving a SERS enhancement factor (EF) up to 2.59 × 10 7 . Ellman's reagent 5,5′-ditho-bis (2-nitrobenzoic acid) (DTNB) was selected as the Raman reactive reporting agent, and the GSH quantification was determined using enzymatic recycling method, and allowed the detection limit of GSH to be down to 74.9 nM using a portable Raman spectrometer. Moreover, the significantly overwhelmed enhancement ratio of GSH over other substances enables the discrimination of GSH detection in complex biofluids.

Charge transfer-induced enhancement of a Raman signal in a hybrid Ag–GaN nanostructure

“…[12][13][14][15][16][17][18] Several other materials, such as silicon, graphene, and actinide-embedded structures, have been used as supporting substrates for distributing Ag and Au nanoparticles to enhance the interactions between the nanoparticles and analyte molecules and consequently improve the limits of detection and enhancement factors. [19][20][21] Similarly, the GaN thin lms of various morphologies (planar and porous) have been used as supports for depositing silver nanoparticles, on which a signicant enhancement in the Raman signal has been reported. 22,23 This wide band-gap semiconductor is an attractive material because of its chemical resistance, high temperature/high power capability, electron saturation velocity, and internal spontaneous and piezoelectric polarization.…”

Investigation on the UV spectra of the supermolecular system involving silver nanoparticles–substituted N‐(phenyl‐ethylene)‐anilines

“…It is known that AgNPs can be bonded to the atoms O, S, and N of organic molecules in light of the report of literature. [21,[30][31][32][33] As regarding the 77 MC of this work, there are 40 samples of 2-H-XPEAYs(I) without 2-OH group and 37 samples of 2-OH-XPEAY (II), which involve 2-OH group and can form intermolecular hydrogen bond. We want to know how do the groups X and Y affect the λ′ max,lim in AgNPs-(I) and AgNPs-(II) solutions.…”

Progress in the Development of SERS-Active Substrates Based on Metal-Coated Porous Silicon

“…The latter strongly depends on the shape and size of the metallic nanostructures and the gaps between them, while porous silicon template helps to manage these properties. The family of the SERS-active nanostructures formed by metal deposition on porous silicon is very rich and includes metallic nanoparticles [ 60 , 61 , 62 , 63 , 64 , 65 , 66 , 67 , 68 , 69 , 70 , 71 , 72 , 73 ] or polydisperse particles [ 74 , 75 , 76 , 77 , 78 , 79 , 80 , 81 , 82 ], dendrites [ 49 , 54 , 83 , 84 ], nanovoids [ 85 ], and metallic oval-shaped NPs [ 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 ]. Figure 2 presents schematic views of plasmonic structures that can be formed with a dependence on porous silicon morphology, doping type, the level of silicon, and the method and conditions of metal deposition.…”