Sunlight Induced Preparation of Functionalized Gold Nanoparticles as Recyclable Colorimetric Dual Sensor for Aluminum and Fluoride in Water

Abstract

A sunlight induced simple green route has been developed for the synthesis of polyacrylate functionalized gold nanoparticles (PAA-AuNPs), in which poly(acrylic acid) functions as a reducing as well as stabilizing agent. This material has been characterized on the basis of spectroscopic and microscopic studies; it exhibited selective colorimetric detection of Al in aqueous media, and the Al induced aggregated PAA-AuNPs exhibited detection of F with sharp color change and high selectivity and sensitivity out of a large number of metal ions and anions tested. The mechanistic study revealed that, for Al, the color change is due to a shift of the SPR band because of the Al induced aggregation of PAA-AuNPs, whereas for F, the reverse color change (blue to red) with return of the SPR band to its original position is due to dispersion of aggregated PAA-AuNPs, as F removes Al from the aggregated species by complex formation. Only concentration-dependent fluoride ion can prevent Al from aggregating PAA-AuNPs. The method is successfully used for the detection of F in water collected from various sources by the spiking method, in toothpastes of different brands by the direct method. The solid Al-PAA-AuNPs were isolated, adsorbed on ZIF@8 (zeolitic imidazolate framework) and on a cotton strip, and applied as solid sensing material for detection of F in aqueous media.

Nanoengineering of Gold Nanoparticles: Green Synthesis, Characterization, and Applications

“…However, polymers are broadly used in the green synthesis of AuNPs. Polymers employed as AuNPs stabilizers consider homopolymers such as poly(N-vinyl-2-pyrrolidone) PVP and poly(acrylic acid) PAA, block copolymers such as poly(ethylene oxide)-b-poly(propylene oxide)-b-poly(ethylene oxide) PEO-PPO-PEO, and polyethylene glycol-g-polyvinyl alcohol PEG-g-PVA, among others [3,[33][34][35][36][37]. Stabilization of metal surfaces using polymers, offers the possibility of tuning the optical properties, functionality, and surface reactivity of metal nanoparticles [31].…”

A Harmonized Applied and Theoretical Exploration for Nanomolar Level Recognition of Perilous F− and CN− by Multichannel Chemosensor: Proposition of Hg2+‐Mediated Logic Gate Imitator

“…[4,42] F À is a conventional component of hypnotics, anesthetics, military nerve gases, psychiatric drugs, cockroach and rat poisons etc., while superfluity (> 1.5 ppm) of this anion causes dental fluorosis, depression, bone malady, collagen fracture, thyroid activity and even cancer. [5][6][7][8] Therefore, recognition of F À even at very low concentration is a noteworthy concern in recent times. [4,9] Conversely, detection of cyanide (CN À ) has also acquired substantial consciousness because of its various fatal consequences on the surroundings and the breathing beings.…”

Colorimetric sensing of iodide ions based on unmodified gold nanoparticles and the distinctive antiaggregation‐to‐aggregation process

“…[ 1,2 ] Gold nanoparticles (AuNPs), as one of the most important metal nanomaterials, have also attracted much attention due to their unique electrical, optical, physical, and chemical properties, such as easy synthesis, high surface‐to‐volume ratio, high extinction coefficients, strong distance dependent optical features, excellent biocompatibility and suitability for surface functionalization [ 3 ] , which provide numerous possibilities for sensing and quantification purposes. So far, various AuNP‐based sensors have been successfully applied to detect different substances (metal ions [ 4–6 ] , anions [ 7,8 ] proteins [ 9,10 ] , small molecules [ 11,12 ] and pathogens [ 13,14 ] ). However, these methods of detecting anions have been relatively less successful compared with other methods and most of the methods needed to modify the AuNP surface, this made the experimental procedure tedious and time‐consuming.…”