Density Functional Theoretical Modeling, Electrostatic Surface Potential and Surface Enhanced Raman Spectroscopic Studies on Biosynthesized Silver Nanoparticles: Observation of 400 pM Sensitivity to Explosives

Sil, Shreekantha; Chaturvedi, Deepika; Krishnappa, Keerthi B; Kumar, Srividya; Asthana, S. N.; Umapathy, Siva

doi:10.1021/jp4090266

Cited by 28 publications

(27 citation statements)

References 69 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Due to the very small length of the cysteamine molecule, the cyteamine-TNT complex is brought to a very short distance from the SERS substrate. [29][30][31] The spectrum also depicted a sharp and intense band at 1348 cm -1 corresponding to NO 2 group symmetric stretching vibration. In addition cysteamine was proven by our group to selectively bind with TNT to form a Meisenheimer while other nitroaromatic compounds such as 2,4-DNt and picric acid did not form a similar complex at pH 8.5 21 .…”

Section: Sers Detection Of Tntmentioning

confidence: 99%

“…Therefore, the Raman spectrum of TNT experiences a high enhancement by the SERS substrate. [29][30][31] The other significant bands appearing at 1292 cm -1 , 1253 cm -1 and 797 cm -1 corresponds to aromatic ring stretching, C 6 H 2 -C vibration and C-H out of plane bending, respectively. Fig.…”

Section: Sers Detection Of Tntmentioning

confidence: 99%

“…In addition cysteamine was proven by our group to selectively bind with TNT to form a Meisenheimer while other nitroaromatic compounds such as 2,4-DNt and picric acid did not form a similar complex at pH 8.5 21 . [29][30][31] The SERS spectrum of cysteamine monolayer alone does not show any 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 significant Raman bands at a concentration of 10 pM. 3A (pink spectrum) depicts the SERS spectrum of the monolayer formed from 1 nM cysteamine-TNT complex.…”

Section: Sers Detection Of Tntmentioning

confidence: 99%

See 2 more Smart Citations

A homogeneous surface-enhanced Raman scattering platform for ultra-trace detection of trinitrotoluene in the environment

et al. 2015

View full text Add to dashboard Cite

A facile and sensitive surface-enhanced Raman scattering substrate was prepared by controlled potentiostatic deposition of closely packed single layer of gold nanostructures (AuNS) over flat gold (pAu) platform. The nanometer scale inter-particle distance between the particles resulted in high population of 'hot spot' which enormously enhanced the scattered Raman photons. A renewed methodology was followed to precisely quantify the SERS substrate enhancement factor (SSEF) and it was estimated as (2.2 ± 0.17) × 10 5 . The reproducibility of the SERS signal acquired by the developed substrate was tested by establishing the relative standard deviation (RSD) of 150 repeated measurements from various locations on the substrate surface.A low RDS of 4.37 confirmed the homogeneity of the developed substrate. The sensitivity of pAu/AuNS was proven by determining 100 fM 2,4,6-trinitrotoluene (TNT) comfortably. As a proof of concept on the potential of the new pAu/AuNS substrate in field analysis, TNT in soil and water matrices was selectively detected after forming a Meisenheimer complex with cysteamine.

show abstract

Section: Sers Detection Of Tntmentioning

confidence: 99%

Section: Sers Detection Of Tntmentioning

confidence: 99%

Section: Sers Detection Of Tntmentioning

confidence: 99%

See 1 more Smart Citation

A homogeneous surface-enhanced Raman scattering platform for ultra-trace detection of trinitrotoluene in the environment

et al. 2015

View full text Add to dashboard Cite

show abstract

“…In the forthcoming studies, we employed pAu/AuNS surface that is modified with AHT monolayer for the SERS based detection of TNT. [25,[52][53][54]. The spectrum also depicts a sharp and intense band at 1375 cm −1 corresponding to NO 2 group symmetric stretching vibration of TNT [25,[52][53][54].…”

Section: Electrochemical and Xps Characterization Of Ca And Aht Modifmentioning

confidence: 91%

“…[25,[52][53][54]. The spectrum also depicts a sharp and intense band at 1375 cm −1 corresponding to NO 2 group symmetric stretching vibration of TNT [25,[52][53][54]. The band at 1559 cm −1 corresponds to asymmetric NO 2 stretching of TNT [25,[52][53][54].…”

Section: Electrochemical and Xps Characterization Of Ca And Aht Modifmentioning

confidence: 92%

Molecular recognition of 2,4,6-trinitrotoluene by 6-aminohexanethiol and surface-enhanced Raman scattering sensor

Jamil

Sivanesan

Izake

et al. 2015

Sensors and Actuators B: Chemical

View full text Add to dashboard Cite

TNT) sensor 6-Aminohexanethiol (AHT) and mixed monolayer Surface-enhanced Raman spectroscopy (SERS) Electrochemical desorption and X-ray photoelectron spectroscopy (XPS) Analysis of explosives in soil a b s t r a c t 2,4,6-Trinitrotoluene (TNT) is one of the most commonly used nitro aromatic explosives in landmine, military and mining industry. This article demonstrates rapid and selective identification of TNT by surface-enhanced Raman spectroscopy (SERS) using 6-aminohexanethiol (AHT) as a new recognition molecule. First, Meisenheimer complex formation between AHT and TNT is confirmed by the development of pink color and appearance of new band around 500 nm in UV-vis spectrum. Solution Raman spectroscopy study also supported the AHT:TNT complex formation by demonstrating changes in the vibrational stretching of AHT molecule between 2800 and 3000 cm −1 . For surface enhanced Raman spectroscopy analysis, a self-assembled monolayer (SAM) of AHT is formed over the gold nanostructure (AuNS) SERS substrate in order to selectively capture TNT onto the surface. Electrochemical desorption and Xray photoelectron studies are performed over AHT SAM modified surface to examine the presence of free amine groups with appropriate orientation for complex formation. Further, AHT and butanethiol (BT) mixed monolayer system is explored to improve the AHT:TNT complex formation efficiency. Using a 9:1 AHT:BT mixed monolayer, a very low detection limit (LOD) of 100 fM TNT was realized. The new method delivers high selectivity towards TNT over 2,4 DNT and picric acid. Finally, real sample analysis is demonstrated by the extraction and SERS detection of 302 pM of TNT from spiked. Crown

show abstract

Space‐Resolved Raman Spectroscopy Applications: From Single Cells to Tissues

Sil

Gautam

Umapathy

2018

Encyclopedia of Analytical Chemistry

View full text Add to dashboard Cite

Raman spectroscopy provides information about the structure, functional groups, and chemical environment of the molecules present in a sample. In recent years, Raman spectroscopic techniques have been extensively used to understand fundamental biology and responses of living systems under diverse physiological and pathological conditions due to its potential to provide multicomponent (chemical) analysis without labeling. Further, Raman spectroscopy provides an upper hand in the study of biofluids in situ owing to low absorption coefficient of water in visible and near‐infrared region in contrast to mid‐infrared region. The incorporation of multivariate data analysis methods provides profound visualization of the complex multicomponent data and thus aid in effective interpretation of Raman spectra. This article reviews recent progress and advents of Raman spectroscopy‐based techniques used for biomedical diagnostics and provides an overview of applications, including biofluids, cells, tissues, and microorganism detection and classification. The spectral information gathered from ex vivo analyses on cells, tissues, and biofluids is important for the interpretation of data acquired in real matrix where it is influenced by unwanted background signals. In the first part of the review, examples on bacterial cells and tissues have been shown to highlight the potential of Raman microspectroscopy to identify and distinguish different bacteria and diseased versus normal tissues. Increased sensitivity of Raman signals have been obtained for the detection of biochemicals such as proteins using surface‐enhanced Raman spectroscopy (SERS) has been depicted. The second half of the article describes the potential of Raman spectroscopy as an in vivo diagnostic tool based on hand‐held fiber probes, spatially offset Raman spectroscopy (SORS) and universal multiple angle Raman spectroscopy (UMARS) along with consideration of clinical translation. In this section, historical development of fiber‐optic Raman probes for biological samples have been described. We have taken specific examples from latest literatures in the field of depth profiling studies to obtain subsurface information toward biomedical diagnostics. Finally, few examples using UMARS towards deep Raman spectroscopy exceeding few tens of millimeters for 3D Raman imaging have been presented.

show abstract

Density Functional Theoretical Modeling, Electrostatic Surface Potential and Surface Enhanced Raman Spectroscopic Studies on Biosynthesized Silver Nanoparticles: Observation of 400 pM Sensitivity to Explosives

Cited by 28 publications

References 69 publications

A homogeneous surface-enhanced Raman scattering platform for ultra-trace detection of trinitrotoluene in the environment

A homogeneous surface-enhanced Raman scattering platform for ultra-trace detection of trinitrotoluene in the environment

Molecular recognition of 2,4,6-trinitrotoluene by 6-aminohexanethiol and surface-enhanced Raman scattering sensor

Space‐Resolved Raman Spectroscopy Applications: From Single Cells to Tissues

Contact Info

Product

Resources

About