scholarly journals Ag-Coated Cellulose Fibers as Surface-Enhanced Raman Scattering Substrates for Adsorptive Detection of Malachite Green

Materials ◽  
2018 ◽  
Vol 11 (7) ◽  
pp. 1197 ◽  
Author(s):  
Yudong Lu ◽  
Changji Wu ◽  
Yang Wu ◽  
Ruiyun You ◽  
Gang Lin ◽  
...  

Surface-enhanced Raman scattering (SERS) is a sensitive technique for the detection of low concentration analytes. In this study, we used cellulose fibers (CF) as the templates for the loading of silver nanoparticles (Ag NPs), and the obtained CF-Ag was applied in the detection of R6G and Malachite Green (MG) by surface-enhanced Raman scattering. The adsorption technique was employed in the sample preparation, and the optimal detecting status was identified in the dynamic range (sample status ranging from wet to dry) for different concentration of analytes. In comparison to Ag NPs, CF-Ag showed enhanced performance for adsorptive detection of Malachite Green, and the limit of detection was 5 × 10−12 M.

Nanomaterials ◽  
2018 ◽  
Vol 8 (7) ◽  
pp. 520 ◽  
Author(s):  
Jia Zhu ◽  
Guanzhou Lin ◽  
Meizhang Wu ◽  
Zhuojie Chen ◽  
Peimin Lu ◽  
...  

Technology transfer from laboratory into practical application needs to meet the demands of economic viability and operational simplicity. This paper reports a simple and convenient strategy to fabricate large-scale and ultrasensitive surface-enhanced Raman scattering (SERS) substrates. In this strategy, no toxic chemicals or sophisticated instruments are required to fabricate the SERS substrates. On one hand, Ag nanoparticles (NPs) with relatively uniform size were synthesized using the modified Tollens method, which employs an ultra-low concentration of Ag+ and excessive amounts of glucose as a reducing agent. On the other hand, when a drop of the colloidal Ag NPs dries on a horizontal solid surface, the droplet becomes ropy, turns into a layered structure under gravity, and hardens. During evaporation, capillary flow was burdened by viscidity resistance from the ropy glucose solution. Thus, the coffee-ring effect is eliminated, leading to a uniform deposition of Ag NPs. With this method, flat Ag NPs-based SERS active films were formed in array-well plates defined by hole-shaped polydimethylsiloxane (PDMS) structures bonded on glass substrates, which were made for convenient detection. The strong SERS activity of these substrates allowed us to reach detection limits down to 10−14 M of Rhodamine 6 G and 10−10 M of thiram (pesticide).


Nanomaterials ◽  
2018 ◽  
Vol 8 (8) ◽  
pp. 629 ◽  
Author(s):  
Yudong Lu ◽  
Ting Zhou ◽  
Ruiyun You ◽  
Yang Wu ◽  
Huiying Shen ◽  
...  

Herein we utilized coordination interactions to prepare a novel core-shell plasmonic nanosensor for the detection of glucose. Specifically, Au nanoparticles (NPs) were strongly linked with Ag+ ions to form a sacrificial Ag shell by using 4-aminothiophenol (4-PATP) as a mediator, which served as an internal standard to decrease the influence of the surrounding on the detection. The resultant Au-PATP-Ag core-shell systems were characterized by UV-vis spectroscopy, transmission electron microscopy, and surface-enhanced Raman scattering (SERS) techniques. Experiments performed with R6G (rhodamine 6G) and CV (crystal violet) as Raman reporters demonstrated that the Au@Ag nanostructure amplified SERS signals obviously. Subsequently, the Au@Ag NPs were decorated with 4-mercaptophenylboronic acid (4-MPBA) to specifically recognize glucose by esterification, and a detection limit as low as 10−4 M was achieved. Notably, an enhanced linearity for the quantitative detection of glucose (R2 = 0.995) was obtained after the normalization of the spectral peaks using 4-PATP as the internal standard. Finally, the practical applicability of the developed sensing platform was demonstrated by the detection of glucose in urine with acceptable specificity.


Sensors ◽  
2018 ◽  
Vol 18 (8) ◽  
pp. 2726 ◽  
Author(s):  
Hannah Dies ◽  
Maria Siampani ◽  
Carlos Escobedo ◽  
Aristides Docoslis

We present a method for the surface-enhanced Raman scattering (SERS)-based detection of toxic contaminants in minimally processed liquid food products, through the use of a dendritic silver nanostructure, produced through electrokinetic assembly of nanoparticles from solution. The dendritic nanostructure is produced on the surface of a microelectrode chip, connected to an AC field with an imposed DC bias. We apply this chip for the detection of thiram, a toxic fruit pesticide, in apple juice, to a limit of detection of 115 ppb, with no sample preprocessing. We also apply the chip for the detection of melamine, a toxic contaminant/food additive, to a limit of detection of 1.5 ppm in milk and 105 ppb in infant formula. All the reported limits of detection are below the recommended safe limits in food products, rendering this technique useful as a screening method to identify liquid food with hazardous amounts of toxic contaminants.


2013 ◽  
Vol 760-762 ◽  
pp. 801-805 ◽  
Author(s):  
Chao Yue Deng ◽  
Gu Ling Zhang ◽  
Bin Zou ◽  
Hong Long Shi ◽  
Yu Jie Liang ◽  
...  

We used a simple low-temperature hydrothermal approach to synthesize Ag nanoparticles (NPs) and demonstrated their efficiency as organic molecule detectors in surface enhanced Raman Scattering (SERS). Using finite difference time domain simulation, we described an investigation on the distribution of electric fields amplitude of the neighboring Ag NPs. The enhanced electric field is confined at the interparticle gaps and the enhancement factor can be further increased with reducing the spacing between the NPs. The theoretical simulation demonstrated good consistency with the experimental measurement results, which predicts an electric fields amplitude enhancement of 115 at the center of NPs gap and an electromagnetic SERS enhancement of 108. The evidence of clear correlations between SERS enhancement and morphology distribution offer a route to develop more effective SERS substrates.


2014 ◽  
Vol 6 (24) ◽  
pp. 9547-9553 ◽  
Author(s):  
Wu-Li-Ji Hasi ◽  
Shuang Lin ◽  
Xiang Lin ◽  
Xiu-Tao Lou ◽  
Fang Yang ◽  
...  

The fabrication of this paper-based SERS substrate is facile and rapid (<10 min). The coverage rate of Ag NPs is relatively high.


1990 ◽  
Vol 44 (1) ◽  
pp. 63-69 ◽  
Author(s):  
J. M. Bello ◽  
T. Vo-Dinh

A fiber-optic system was developed for exciting and collecting surface-enhanced Raman scattering (SERS) signals generated from a sensing plate tip having silver-coated microparticles deposited on a glass support. Various fiber parameters, such as fiber type, fiber-substrate geometry, and other experimental parameters, were investigated to obtain the optimum conditions for the SERS fiber-optic device. In addition, analytical figures of merit relevant to the performance of the SERS fiber-optic sensor, such as SERS spectral characteristics, reproducibility, linear dynamic range, and limit of detection, were also investigated.


2015 ◽  
Vol 113 (2) ◽  
pp. 268-273 ◽  
Author(s):  
Shikuan Yang ◽  
Xianming Dai ◽  
Birgitt Boschitsch Stogin ◽  
Tak-Sing Wong

Detecting target analytes with high specificity and sensitivity in any fluid is of fundamental importance to analytical science and technology. Surface-enhanced Raman scattering (SERS) has proven to be capable of detecting single molecules with high specificity, but achieving single-molecule sensitivity in any highly diluted solutions remains a challenge. Here we demonstrate a universal platform that allows for the enrichment and delivery of analytes into the SERS-sensitive sites in both aqueous and nonaqueous fluids, and its subsequent quantitative detection of Rhodamine 6G (R6G) down to ∼75 fM level (10−15 mol⋅L−1). Our platform, termed slippery liquid-infused porous surface-enhanced Raman scattering (SLIPSERS), is based on a slippery, omniphobic substrate that enables the complete concentration of analytes and SERS substrates (e.g., Au nanoparticles) within an evaporating liquid droplet. Combining our SLIPSERS platform with a SERS mapping technique, we have systematically quantified the probability, p(c), of detecting R6G molecules at concentrations c ranging from 750 fM (p > 90%) down to 75 aM (10−18 mol⋅L−1) levels (p ≤ 1.4%). The ability to detect analytes down to attomolar level is the lowest limit of detection for any SERS-based detection reported thus far. We have shown that analytes present in liquid, solid, or air phases can be extracted using a suitable liquid solvent and subsequently detected through SLIPSERS. Based on this platform, we have further demonstrated ultrasensitive detection of chemical and biological molecules as well as environmental contaminants within a broad range of common fluids for potential applications related to analytical chemistry, molecular diagnostics, environmental monitoring, and national security.


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