Simple approach of synthesis of stable Gold nanoparticles, characterization and study of various parameters for arsenic detection (original) (raw)
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Chemiluminescence catalysed by gold nanoparticles for the analysis of arsenic (III) in real water
Journal of Experimental Nanoscience, 2016
A gold nanoparticle (AuNPs)-catalysed chemiluminescence (CL) method is developed for the analysis of As 3C cations by detecting the enhancement of the luminol-H 2 O 2 reaction by AuNPs. AuNPs of different sizes were prepared by a chemical method. The size and shape of these nanoparticles were determined by transmission electron microscopy. The various parameters of the reaction media such as the pH and the concentration of H 2 O 2 and luminol were optimised. The enhancement of the CL intensity may be as a result of energy transfer by the AuNPs or plasmon-induced enhancement. The interaction of the AuNPs with As 3C amplified the CL signal. This amplified CL was used to detect As 3C in real water samples. The linear region of the calibration curve from 0.3 to 4 mg/L shows that this is a suitable method for the detection of low concentrations of arsenic (III).
Angewandte Chemie, 2009
The contamination of drinking water with arsenic poses a threat to global health. [1a-e] As many as 140 million people worldwide may have been exposed to drinking water with arsenic contamination levels higher than the World Health Organizations (WHO) guideline of 10 ppb. [1a] The major arsenic species found in environmental samples are inorganic arsenite (As III ) and arsenate (As V ) salts, organic forms of arsenic, for example, dithioarsenate (DTA), dimethylarsinic acid (DMA), and monomethylarsinic acid (MMA). [1b-f] Current technology based on laboratory-based analytical procedures [2a,b] is time-consuming and relies on a series of enrichment steps. As a result, the development of ultrasensitive assays for the real-time detection of arsenic has attracted considerable research efforts in recent years. [2c-f, 3a,b] Noblemetal nanostructures attract much interest because of their unique properties, including large optical field enhancements that result in the strong scattering and absorption of light. [3a-n] In the last 15 years, the field of biological and chemical sensors that use nanomaterials has witnessed an explosion because of the unique optical properties of nanomaterials. [3a-n] Very recently, a surface-enhanced Raman scattering (SERS) based assay [3a] and surface plasmon resonance (SPR) sensors [3b] have been reported for arsenic detection down to 1 ppb, which is an order of magnitude lower than WHO guidelines. [1a] However, these assays are not selective against alkali-, alkaline-earth-and heavy-transition-metal ions. Such selectivity is essential for applications to real environmental samples. Herein, we report a glutathione (GSH), dithiothreitol (DTT), and cysteine (Cys) modified gold-nanoparticlebased dynamic light scattering (DLS) assay for the label-free selective detection of arsenic, with an excellent detection limit (10 ppt) and selectivity over other analytes.
Synthesis and Applications of Gold Nanoparticle Probes
CHINESE JOURNAL OF ANALYTICAL CHEMISTRY (CHINESE VERSION), 2010
During the last decade, gold nanoparticles (AuNPs)-based assays have been well developed and widely used in biological analysis and biomedical detections because AuNPs have unique physical and chemical properties, which are extremely sensitive to environmental conditions (e.g., size, shape, ligand, and degree of aggregation). In particular, the AuNPs-based assays have already been used for detecting practical samples with high simplicity and selectivity. This review discusses the recent development of the synthesis and biological molecular functionalization of AuNPs and their applications on cellular analysis and detections of the heavy metallic cations, small organic compounds, nucleic acids, and proteins.
A modified and simplified method for purification of gold nanoparticles
MethodsX, 2020
2 nm gold nanoparticles (AuNPs) have promising applications within drug and protein delivery, bioimaging, and biosensing. By performing ligand place-exchange reactions, AuNPs protected with alkanethiolate ligands can be functionalized to regulate their behaviors. In this reaction, a new ligand is incorporated by mixing a thiol with the AuNPs. To remove the excess new ligand as well as the displaced thiolate, dialysis has previously been the most widely used method. However, this purification method is time-consuming and fails to remove unwanted thiols completely. In this study, we describe a fast and efficient procedure to purify AuNP aqueous solution through liquid-liquid extraction using dichloromethane. • We demonstrate a facile way to purify AuNPs after ligand place-exchange reactions through liquid-liquid extraction. • Liquid-liquid extraction is a simple, inexpensive and efficient method for AuNP purification. • This protocol enables us to completely purify AuNPs in a few hours and can be used as a much quicker and more scaleable valid alternative to dialysis.
Electrochemical detection of arsenic on a gold nanoparticle array
Russian Journal of Physical Chemistry A, 2007
The detection of As(III) was investigated on a gold nanoparticle array. At the first stage, gold nanoparticles were synthesized on glassy carbon microspheres. The resulting hybrid material was characterized by SEM and the sizes of the nanoparticles were found to be in the range 20-200 nm. At the second stage, glassy carbon microspheres decorated with Au nanoparticles were abrasively attached to the surface of a basal-plane pyrolytic electrode. The resulting gold nanoarray was characterized by the reduction of surface gold oxides. Furthermore, it was found to have good characteristics for the sensing of arsenic via anodic stripping voltammetry with a limit of detection of 0.8 µ M and a sensitivity of 0.91 C M -1 .
Simple spectrophotocolorimetric method for quantitative determination of gold in nanoparticles
Talanta, 2011
A simple spectrophotocolorimetric method devoted to the measurement of gold content in nanoparticles (NPs) was developed. It includes two steps: (i) metal gold NPs (Au NPs) are oxidized into the AuCl 4 − anion using a 5 × 10 −2 M HCl-1.5 × 10 −2 M NaCl-7 × 10 −4 M Br 2 solution, next (ii) AuCl 4 − concentration is measured using a spectrophotometric assay based on the reaction of AuCl 4 − with the cationic form of Rhodamine B to give a violet ion pair complex. This latter is extracted with diisopropyl ether and the absorbance of the organic complex is measured at 565 nm. The method is linear in the range 6-29 M of AuCl 4 − with a limit of detection of 4.5 M. The analytical method was optimized with respect of bromine excess to obtain complete Au NPs oxidation. The method was applied to two types of Au NPs currently under investigation: citrate-stabilized Au NPs and Au NPs capped with dihydrolipoic acid (Au@DHLA). Both the gold content of Au NPs and the concentration of NPs (using NP diameter measured by transmission electron microscopy) have been calculated.
Detection of pathogen based on the catalytic growth of gold nanocrystals
Water Research, 2009
A homogenous detection of pathogen (Giardia lamblia cysts) based on the catalytic growth of gold nanoparticles (AuNPs) has been studied. In this study, centrifugal filters were employed as tools to concentrate and separate the pathogen cells, and moreover amplify the detection signal. The catalytic growth of gold nanoparticles was verified to be positively related to gold seeds concentration. On this basis, homogenous detection of the pathogenic bacteria in liquid phase was established by means of conjugating antibody to gold seeds.