pH-Triggered Molecular Alignment for Reproducible SERS Detection via an AuNP/Nanocellulose Platform

There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

Abstract

The low affinity of neutral and hydrophobic molecules towards noble metal surfaces hinders their detection by surface-enhanced Raman spectroscopy (SERS). Herein, we present a method to enhance gold nanoparticle (AuNP) surface affinity by lowering the suspension pH below the analyte pK _a. We developed an AuNP/bacterial cellulose (BC) nanocomposite platform and applied it to two common pollutants, carbamazepine (CBZ) and atrazine (ATZ) with pK _a values of 2.3 and 1.7, respectively. Simple mixing of the analytes with AuNP/BC at pH < pK _a resulted in consistent electrostatic alignment of the CBZ and ATZ molecules across the nanocomposite and highly reproducible SERS spectra. Limits of detection of 3 nM and 11 nM for CBZ and ATZ, respectively, were attained. Tests with additional analytes (melamine, 2,4-dichloroaniline, 4-chloroaniline, 3-bromoaniline, and 3-nitroaniline) further illustrate that the AuNP/BC platform provides reproducible analyte detection and quantification while avoiding the uncontrolled aggregation and flocculation of AuNPs that often hinder low pH detection.

Related collections

Most cited references 27

Record: found
Abstract: found
Article: not found

Determination of organic compounds in water using dispersive liquid-liquid microextraction.

Mohammad Rezaee, Yaghoub Assadi, Mohammad-Reza Milani Hosseini … (2006)

A new microextraction technique termed dispersive liquid-liquid microextraction (DLLME) was developed. DLLME is a very simple and rapid method for extraction and preconcentration of organic compounds from water samples. In this method, the appropriate mixture of extraction solvent (8.0 microL C2Cl4) and disperser solvent (1.00 mL acetone) are injected into the aqueous sample (5.00 mL) by syringe, rapidly. Therefore, cloudy solution is formed. In fact, it is consisted of fine particles of extraction solvent which is dispersed entirely into aqueous phase. After centrifuging, the fine particles of extraction solvent are sedimented in the bottom of the conical test tube (5.0 +/- 0.2 microL). The performance of DLLME is illustrated with the determination of polycyclic aromatic hydrocarbons (PAHs) in water samples by using gas chromatography-flame ionization detection (GC-FID). Some important parameters, such as kind of extraction and disperser solvent and volume of them, and extraction time were investigated. Under the optimum conditions the enrichment factor ranged from 603 to 1113 and the recovery ranged from 60.3 to 111.3%. The linear range was 0.02-200 microg/L (four orders of magnitude) and limit of detection was 0.007-0.030 microg/L for most of analytes. The relative standard deviations (RSDs) for 2 microg/L of PAHs in water by using internal standard were in the range 1.4-10.2% (n = 5). The recoveries of PAHs from surface water at spiking level of 5.0 microg/L were 82.0-111.0%. The ability of DLLME technique in the extraction of other organic compounds such as organochlorine pesticides, organophosphorus pesticides and substituted benzene compounds (benzene, toluene, ethyl benzene, and xylenes) from water samples were studied. The advantages of DLLME method are simplicity of operation, rapidity, low cost, high recovery, and enrichment factor.

0 comments Cited 411 times – based on 0 reviews      Review now

Bookmark

Record: found
Abstract: found
Article: not found

Gold nanoparticle based label-free SERS probe for ultrasensitive and selective detection of trinitrotoluene.

Samuel Dasary, Anant Kumar Singh, Dulal Senapati … (2009)

TNT is one of the most commonly used nitro aromatic explosives used for landmine and military purpose. Due to the significant detrimental effects, contamination of soil and groundwater with TNT is the major concern. Driven by the need to detect trace amounts of TNT from environmental samples, this article demonstrates for the first time a highly selective and ultra sensitive, cysteine modified gold nanoparticle based label-free surface enhanced Raman spectroscopy (SERS) probe, for TNT recognition in 2 pico molar (pM) level in aqueous solution. Due to the formation of Meisenheimer complex between TNT and cysteine, gold nanoparticles undergo aggregation in the presence of TNT via electrostatic interaction between Meisenheimer complex bound gold nanoparticle and cysteine modified gold nanoparticle. As a result, it formed several hot spots and provided a significant enhancement of the Raman signal intensity by 9 orders of magnitude through electromagnetic field enhancements. A detailed mechanism for termendous SERS intensity change has been discussed. Our experimental results show that TNT can be detected quickly and accurately without any dye tagging in lower pM level with excellent discrimination against other nitro compounds and heavy metals.

0 comments Cited 115 times – based on 0 reviews      Review now

Bookmark

Record: found
Abstract: found
Article: not found

Occurrence and fate of carbamazepine, clofibric acid, diclofenac, ibuprofen, ketoprofen, and naproxen in surface waters.

Céline Tixier, Heinz Singer, Sjef Oellers … (2003)

Although various single-concentration measurements of pharmaceuticals are available in the literature, detailed information on the variation over time of the concentration and the load in wastewater effluents and rivers and on the fate of these compounds in the aquatic environment are lacking. We measured the concentrations of six pharmaceuticals, carbamazepine, clofibric acid, diclofenac, ibuprofen, ketoprofen, and naproxen, in the effluents of three wastewater treatment plants (WWTPs), in two rivers and in the water column of Lake Greifensee (Switzerland) over a time period of three months. In WWTP effluents, the concentrations reached 0.95 microg/L for carbamazepine, 0.06 microg/L for clofibric acid, 0.99 microg/L for diclofenac, 1.3 microg/L for ibuprofen, 0.18 microg/L for ketoprofen, and 2.6 microg/L for naproxen. The relative importance in terms of loads was carbamazepine, followed by diclofenac, naproxen, ibuprofen, clofibric acid, and ketoprofen. An overall removal rate of all these pharmaceuticals was estimated in surface waters, under real-world conditions (in a lake), using field measurements and modeling. Carbamazepine and clofibric acid were fairly persistent. Phototransformation was identified as the main elimination process of diclofenac in the lake water during the study period. With a relatively high sorption coefficient to particles, ibuprofen might be eliminated by sedimentation. For ketoprofen and naproxen, biodegradation and phototransformation might be elimination processes. For the first time, quantitative data regarding removal rates were determined in surface waters under real-world conditions. All these findings are important data for a risk assessment of these compounds in surface waters.

0 comments Cited 112 times – based on 0 reviews      Review now

Bookmark

All references

Author and article information

Journal

Journal ID (nlm-ta): Sci Rep

Journal ID (iso-abbrev): Sci Rep

Title: Scientific Reports

Publisher: Nature Publishing Group

ISSN (Electronic): 2045-2322

Publication date (Electronic): 11 December 2015

Publication date Collection: 2015

Volume: 5

Electronic Location Identifier: 18131

Affiliations

[1 ]Department of Civil and Environmental Engineering, Virginia Tech , Blacksburg, Virginia

[2 ]Virginia Tech Institute of Critical Technology and Applied Science (ICTAS) Sustainable Nanotechnology Center (VTSuN ), Blacksburg, Virginia

[3 ]Center for the Environmental Implications of Nanotechnology (CEINT), Duke University , Durham, North Carolina

Author notes

[a ] pvikes@ 123456vt.edu

Article

Publisher Item ID: srep18131

DOI: 10.1038/srep18131

PMC ID: 4676058

PubMed ID: 26658696

SO-VID: fe28aded-feb7-4bb3-aa6b-7eb46f58391e

License:

This work is licensed under a Creative Commons Attribution 4.0 International License. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder to reproduce the material. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/

pH-Triggered Molecular Alignment for Reproducible SERS Detection via an AuNP/Nanocellulose Platform

Read this article at

Abstract

Related collections

Reproducible research article collection

Most cited references 27

Determination of organic compounds in water using dispersive liquid-liquid microextraction.

Gold nanoparticle based label-free SERS probe for ultrasensitive and selective detection of trinitrotoluene.

Occurrence and fate of carbamazepine, clofibric acid, diclofenac, ibuprofen, ketoprofen, and naproxen in surface waters.

Author and article information

Journal

Affiliations

Author notes

Article

History

Categories

Comments

Comment on this article

Similar content 66

Cited by 13

Most referenced authors 436