Different behaviors in the transformation of PATP adsorbed on Ag or Au nanoparticles investigated by surface-enhanced Raman spectroscopy – A study of the effects from laser energy and annealing

Xu, Jianfang; Luo, Shiyi; Liu, Guokun

doi:10.1016/j.saa.2015.02.039

Cited by 15 publications

(14 citation statements)

References 27 publications

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“…Additionally, the chemically active Ag coating provides faster PATP-to-DMAB conversion compared to the Au coating of the same thickness (see also Fig. S4 in Supporting information) [44] higher reactivity of the silver toward the hydrogen sulfide [45] and its derivatives, responsible for easier formation of a charge transfer complex and chemical amplification, it have been reported that the formation of DMAB on the Ag surfaces is much easier under the same experimental condition than that on Au ones, considering an easier formation and a higher activity of triplet oxygen molecules ( 3 O 2 ) on the Ag surfaces [46,47]. Furthermore, with the activation of 3 O 2 species driven by plasmon resonances, the 514.5 nm excitation was shown to be more efficient for DMAB formation on the Ag surfaces, whereas, the 632.8 nm excitation was preferred on the Au ones [47].…”

Section: Resultsmentioning

confidence: 99%

Chemically non-perturbing SERS detection of a catalytic reaction with black silicon

et al. 2018

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All-dielectric resonant micro- and nano-structures made of high-index dielectrics have recently emerged as a promising surface-enhanced Raman scattering (SERS) platform which can complement or potentially replace the metal-based counterparts in routine sensing measurements. These unique structures combine the highly-tunable optical response and high field enhancement with the non-invasiveness, i.e. chemically non-perturbing the analyte, simple chemical modification and recyclability. Meanwhile, commercially competitive fabrication technologies for mass production of such structures are still missing. Here, we attest a chemically inert black silicon (b-Si) substrate consisting of randomly-arranged spiky Mie resonators for a true non-invasive (chemically non-perturbing) SERS identification of the molecular fingerprints at low concentrations. Based on the comparative in situ SERS tracking of the para-aminothiophenol (PATP)-to-4,4'-dimercaptoazobenzene (DMAB) catalytic conversion on the bare and metal-coated b-Si, we justify the applicability of the metal-free b-Si for ultra-sensitive non-invasive SERS detection at a concentration level as low as 10-6 M. We performed supporting finite-difference time-domain (FDTD) calculations to reveal the electromagnetic enhancement provided by an isolated spiky Si resonator in the visible spectral range. Additional comparative SERS studies of the PATP-to-DMAB conversion performed with a chemically active bare black copper oxide (b-CuO) substrate as well as SERS detection of the slow daylight-driven PATP-to-DMAB catalytic conversion in the aqueous methanol solution loaded with colloidal silver nanoparticles (Ag NPs) confirm the non-invasive SERS performance of the all-dielectric crystalline b-Si substrate. A proposed SERS substrate can be fabricated using the easy-to-implement scalable technology of plasma etching amenable on substrate areas over 10 × 10 cm2 making such inexpensive all-dielectric substrates promising for routine SERS applications, where the non-invasiveness is of high importance.

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Section: Resultsmentioning

confidence: 99%

Chemically non-perturbing SERS detection of a catalytic reaction with black silicon

et al. 2018

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“…From these results, it is obvious that the threshold of the chemical transformation falls down on the AgNP array. The lower threshold of the chemical transformation was achieved with the activation of the oxygen by the enhanced EM field, , the inherent catalytic property of silver, and plasmonic heating. The AgNP array promotes the chemical transformation where the AgNP substrate works not only as plasmonic surface but also as catalytic surface.…”

Section: Results and Discussionmentioning

confidence: 99%

Laser Power Threshold of Chemical Transformation on Highly Uniform Plasmonic and Catalytic Nanosurface

2016

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Noble metallic nanosurface exhibits both plasmonic and catalytic functions. Surface-enhanced Raman scattering of para-aminothiophenol (p-ATP) was measured on a highly uniform two-dimensional silver nanoparticle array at different intensities of an excitation laser (532 nm) ranging from 4 to 4000 W/mm 2 . It was observed that p-ATP was chemically transformed to 4,4′-dimercaptoazobenzene (DMAB) with the laser intensities of ≥40 W/mm 2 during the Raman measurement. At 4 W/mm 2 , the Raman peaks of DMAB disappeared, which indicates that the laser intensity was insufficient for the chemical transformation although it was sufficient for the Raman measurement. The highly uniform silver nanoparticle array allowed quantitative analysis on the Raman peak intensity. The threshold of the chemical transformation from p-ATP to DMAB was estimated to be ∼18.8 W/mm 2 on the silver nanoparticle array whose enhancement factor is ∼10 4 .

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“…The structural changes were also monitored by SERS analysis. As shown in Figure 2 e, the Au-PATP-Ag core-shell NPs featured enhanced Raman signals of the internal standard, 4-PATP, at 1584, 1435, 1388, 1146 and 1077 cm −1 (i.e., all these results indicated that “hot spots” were formed inside the Au@Ag nanostructure) [ 39 , 40 ].…”

Section: Resultsmentioning

confidence: 99%

“…Herein, we used 4-aminothiophenol (4-PATP) to connect Au NPs and Ag NPs to form Au@Ag core-shell nanostructures, which are subsequently modified with 4-MPBA to specifically recognize glucose ( Figure 1 ). The use of the small molecules (e.g., 4-PATP) [ 38 ] as templates to fabricate intra-gap core-shell structures results in the generation of “hot spots” that can enhance the Raman signal intensity of these molecules [ 39 , 40 ]. Moreover, since 4-PATP molecules presented inside the shell are not subject to the adverse effects of the external environment or desorption, they can also act as the internal standards.…”

Section: Introductionmentioning

confidence: 99%

Fabrication and Characterization of a Highly-Sensitive Surface-Enhanced Raman Scattering Nanosensor for Detecting Glucose in Urine

Zhou²,

You³

et al. 2018

Nanomaterials

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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.

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Different behaviors in the transformation of PATP adsorbed on Ag or Au nanoparticles investigated by surface-enhanced Raman spectroscopy – A study of the effects from laser energy and annealing

Cited by 15 publications

References 27 publications

Chemically non-perturbing SERS detection of a catalytic reaction with black silicon

Chemically non-perturbing SERS detection of a catalytic reaction with black silicon

Laser Power Threshold of Chemical Transformation on Highly Uniform Plasmonic and Catalytic Nanosurface

Fabrication and Characterization of a Highly-Sensitive Surface-Enhanced Raman Scattering Nanosensor for Detecting Glucose in Urine

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