Detection of chemical pollutants in water using gold nanoparticles as sensors: a review

Abstract

Rapid and accurate evaluation of pollutant contamination in water is one of the key tasks of environmental monitoring. To make onsite assessment feasible, the analytical tools should be easy to operate, with minimal sample preparation needs. Gold nanoparticle (AuNP)-based sensors have the potential to detect toxins, heavy metals, and inorganic and organic pollutants in water rapidly with high sensitivity, and they are expected to play an increasingly important role in environmental monitoring. In this article, the synthesis, fabrication and functionalization of AuNPs are discussed, and the recent advances in the development and application of AuNP-based sensors for the determination of various pollutants contamination in water are reviewed.

Biogenic Silver Nanoparticles as Sensors of Cu²⁺ and Pb²⁺ in Aqueous Solutions

“…These nanoparticles are stable at pH 5.27; in this pH range the carboxylic moieties of the capping biomolecules are present in the ionized form, which increase the electronic interaction with the surface of the silver nanoparticle. The addition of Pb 2+ and Cu 2+ ions into the nanoparticles solution results also in a bathochromic shift in the plasmon absorption band as shown in Figure 5a, from 400 to 426nm and 403 to 412nm for lead and copper ions, respectively [23,25,28,35]. These shifts in the plasmon absorption band and the visual color change (Figure 5a and 5b) can be likewise attributed to the formation of aggregates of Ag-NPs and the lead (II) and copper (II) ions [25][26][27]36].…”

“…preferentially bind to the carboxylic group in phenolic compounds [18,27,28]. A decrease in the intensity of the plasmon absorption at 400nm with time was observed (Figure 5a) when the Ag-NPs solution and the metal ions solutions were put in contact.…”

“…The majority of chromoionopheres available for the detection are soluble in organic solvents, which limit the day-to-day applications and pollute even more the environment [25][26][27][28]. It is desirable to find procedures for selective naked-eye detection of metal ions in aqueous media that do not require a specific instrumentation, especially for field-test [23].…”

“…Optical reports methodologies listed in the literature for the detection of metal ions are base the surface plasmon resonance of silver nanoparticles, due to dependence of the plasmon shift with the chemical environment surrounding the Ag nanoparticles [29][30][31]. Moreover, surface plasmon resonance applied to colorimetric sensors does not require a uniform size and shape of the nanoparticles [28].…”

Precision Target Guide Strategy for Applying SERS into Environmental Monitoring

“…Different techniques including chromatography, spectroscopy, mass-spectra methods are well established in environmental analysis [3][4][5], but most of these methods require sophisticated instruments and some of them are lack of sufficiently recognition capacity, which limit their wide applications for infield application. Recently, advanced nanomaterial-based methods have contributed a lot to this area, such as microfluidics, electrochemical sensor, surface plasmon resonance (SPR) method, single-molecule spectroscopy and hyperspectroscopy [6][7][8].…”