Surface Enhanced Raman Spectroscopy Of AgTCNQ Formed From Ag Micellar And Inverse Micellar Colloidal Systems

1995 ◽  
Vol 413 ◽  
Author(s):  
Ivan W. Ong ◽  
Dwaine O. Cowan ◽  
Theodore O. Poehler
Keyword(s):  
Colloidal Particles ◽  
Optical Memory ◽  
Surface Enhanced Raman Spectroscopy ◽  
Memory Storage ◽  
Colloidal Systems ◽  
Laser Raman ◽  
The Past ◽  
Storage Media ◽  
Surface Enhanced ◽  
Surface Enhanced Raman

ABSTRACTSilver Tetracyanoquinodimethane (AgTCNQ) is an organometallic semiconductingcompound with potential for use as an optical memory storage media due to its ability to exist intwo states. A laser Raman system has been proposed for this application as the two states havedistinct Raman vibrational peaks. However, the Raman spectra of bulk AgTCNQ films is veryweak and requires special measures to prevent laser-induced degradation and to ensure adequatesignal to noise ratios. In this paper, we report a synthesis AgTCNQ consisting of AgTCNQnanolayers grown around silver colloidal particles in both water and heptane with the use of theamphiphilic surfactants, AOT and SDS. The Raman scattering of such AgTCNQ systems hasbeen found to be strongly enhanced and far superior to that obtained on bulk AgTCNQ films.We believe that such a system represents a novel and advantageous way of detecting theswitching behavior of AgTCNQ (and other metal-TCNQ compounds) by laser, as Ramanresearch on metal-TCNQ systems has been stymied in the past by poor Raman signals andsusceptibility to laser-induced degradation.

scholarly journals An Expedient SERS Strip Tactic for Rapid On-Site Detection with Long-Time Sensitivity and Repeatability

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Chen Wang ◽  
Yueqian Wan ◽  
Yong Su ◽  
Yafei Cai ◽  
Shengjun Xiong ◽  
...  
Keyword(s):  
Colloidal Particles ◽  
Rhodamine 6G ◽  
Surface Enhanced Raman Spectroscopy ◽  
Dip Coating ◽  
Animal Blood ◽  
Discrimination Capability ◽  
Time Sensitivity ◽  
Surface Enhanced ◽  
Surface Enhanced Raman ◽  
Long Time

Surface-enhanced Raman spectroscopy (SERS) has attracted lots of interest in academic and industrial fields in recent years. The improvement in long-time sensitivity and repeatability is highly demanded by the on-site applications. Herein, we present an expedient SERS strip tactic with these desired advantages. Specifically, the tactic utilized the outstanding stability of colloidal particles to maintain the SERS materials during the storage. Upon usage, the strip is rapidly prepared on-site, and then the targets were sampled with a dip-coating and heating method, which is designed to standardize the whole detection process with the sensitivity kept. Thanks to the tactic, only one-third of SERS sensitivity decay was observed for rhodamine 6G after half a year. Besides rhodamine 6G, the SERS spectra of different animal blood samples were also investigated with the SERS strip tactic, and a species-based discrimination capability was preliminarily demonstrated.

scholarly journals Colloidal core–shell materials with ‘spiky’ surfaces assembled from gold nanorods

2014 ◽  
Vol 50 (60) ◽  
pp. 8157-8160 ◽  
Author(s):  
Iris W. Guo ◽  
Idah C. Pekcevik ◽  
Michael C. P. Wang ◽  
Brandy K. Pilapil ◽  
Byron D. Gates
Keyword(s):  
Raman Spectroscopy ◽  
Gold Nanorods ◽  
Self Assembly ◽  
Colloidal Particles ◽  
Surface Enhanced Raman Spectroscopy ◽  
The Self ◽  
Core Shell ◽  
Surface Enhanced ◽  
Resonance Properties ◽  
Surface Enhanced Raman

Colloidal particles are prepared with a ‘spiky’ surface topography achieved by the self-assembly of gold nanorods onto the surfaces of spherical polystyrene cores. These core–shell assemblies exhibit surface plasmon resonance properties and serve as a platform for surface-enhanced Raman spectroscopy measurements.

Surface-Enhanced Raman Spectroscopy of Bacteria and Pollen

2005 ◽  
Vol 59 (8) ◽  
pp. 1016-1023 ◽  
Author(s):  
Atanu Sengupta ◽  
Mary L. Laucks ◽  
E. James Davis
Keyword(s):  
Biological Material ◽  
Colloidal Particles ◽  
Populus Deltoides ◽  
Poa Pratensis ◽  
Volume Ratio ◽  
Kentucky Bluegrass ◽  
Surface Enhanced Raman Spectroscopy ◽  
Metallic Surface ◽  
Surface Enhanced ◽  
Surface Enhanced Raman

A technique for distinguishing biological material based on surface-enhanced Raman scattering (SERS) is reported in this work. Of particular interest is biological material that can be airborne. Silver colloidal particles with diameters in the range 10 to 20 nm and with a characteristic ultraviolet–visible (UV-VIS) absorption band at 400 nm were used to obtain SERS spectra of Escherichia coli, Pseudomonas aeruginosa, and Salmonella typhimurium bacteria and a number of tree and grass pollens ( Cupressus arizonica (cypress), Sequoia sempervirens (redwood), Populus deltoides (cottonwood), Poa pratensis (Kentucky bluegrass), and Anthoxanthum odoratum (sweet vernal grass)). While differences in the SERS spectra among the bacteria were small, we found that the pollen spectra we analyzed could readily be distinguished from the bacteria spectra, and there were significant differences between pollen from different families. In order to obtain reproducible results, we studied the parameters controlling the interaction between the analyte and the nanoscale metallic surface. Our results show that the volume ratio of analyte to colloidal particles must be within a narrow range of values to optimize the signal-to-noise ratio of the SERS spectra and minimize the fluorescence from the analyte. Also, we found that the time-dependent behavior of colloidal/bacterial suspensions (or adsorption rate of the silver colloid particles on the bacteria) is strongly dependent on pH, density of bacteria in solution, and even, to some extent, the type of bacteria.

Nanozyme-Based Biosensors for Exogenous Contaminant Detection in Foods

2021 ◽  
Vol 18 ◽  
Author(s):  
Yujiao Hou ◽  
Boyu Jia ◽  
Xiaofang Liao ◽  
Lizhu Fu ◽  
Xin Zhang ◽  
...  
Keyword(s):  
Food Safety ◽  
Low Cost ◽  
Surface Enhanced Raman Spectroscopy ◽  
The Past ◽  
Real World Application ◽  
Contaminant Detection ◽  
Simple Preparation ◽  
Surface Enhanced ◽  
Surface Enhanced Raman ◽  
Global Concern

: Abstract Food safety arising from exogenous contaminants has become a global concern. The development of simple, rapid and sensitive methods for effective detection and management of trace levels of exogenous contaminants has emerged as a hotspot, as well as the important priorities in food industry. Nanozymes that are defined as the emerging enzyme-like nanomaterials with robust catalytic activity, simple preparation, high stability, and low cost have been widely used in construction of biosensors for detection of hazardous contaminants in foods, greatly accelerating the advancement of food safety assay. In this review, we comprehensively summarize the recent advances of nanozyme-based biosensors, such as colorimetric, electrochemical, photoelectrochemical and surface-enhanced Raman spectroscopy-based sensors, over the past five years for the detection of various exogenous contaminants including mycotoxins, heavy metals, pesticides, antibiotics, pathogens and microcystins in foods. Beyond a highlight of the advantages and limitations in real-world application, we critically propose the current challenges and future trends of these biosensors for exogenous contaminant detection in foods to guarantee their quality and safety.

Surface-enhanced Raman spectroscopy: bottlenecks and future directions

2018 ◽  
Vol 54 (1) ◽  
pp. 10-25 ◽  
Author(s):  
Rajapandiyan Panneerselvam ◽  
Guo-Kun Liu ◽  
Yao-Hui Wang ◽  
Jun-Yang Liu ◽  
Song-Yuan Ding ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Surface Enhanced Raman Spectroscopy ◽  
Future Perspectives ◽  
Future Directions ◽  
Feature Article ◽  
The Past ◽  
Early Stages ◽  
Surface Enhanced ◽  
Surface Enhanced Raman

This feature article discusses developmental bottleneck issues in surface Raman spectroscopy in its early stages and surface-enhanced Raman spectroscopy (SERS) in the past four decades and future perspectives.

scholarly journals Graphene/TiO2 hybrid layer for simultaneous detection and degradation by a one-step transfer and integration method

RSC Advances ◽  
2017 ◽  
Vol 7 (25) ◽  
pp. 14959-14965 ◽  
Author(s):  
Xinxin Yu ◽  
Ranran Cai ◽  
Yuqing Song ◽  
Qiang Gao ◽  
Nan Pan ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Integration Method ◽  
Simultaneous Detection ◽  
Surface Enhanced Raman Spectroscopy ◽  
Sers Substrate ◽  
Hybrid Layer ◽  
The Past ◽  
Surface Enhanced ◽  
Surface Enhanced Raman ◽  
One Step

During the past decades, researchers have made great efforts towards an ideal surface enhanced Raman spectroscopy (SERS) substrate.

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