Selective Interactions of Al(III) with Plasmonic AgNPs by Colorimetric, Kinetic, and Thermodynamic Studies

Abstract

In this paper, we report a simple, novel, and highly selective plasmonic nanoparticles (NPs)-based colorimetric nanoprobe for the detection of Al(III) ions in aqueous solution. 5-Hydroxy indole-2-carboxylic acid (5H-I2CA) was utilized as a reducing as well as capping agent for the preparation of silver nanoparticles (5H-I2CA@AgNPs). The interaction between Al(III) and AgNPs was determined by UV–vis absorption spectroscopy, high-resolution transmission electron microscopy, Fourier transform infrared, X-ray photoelectron spectroscopy, and dynamic light scattering techniques. The absorption values ( A 452–410 ) of the 5H-I2CA@AgNPs solution exhibited a linear correlation with Al(III) ion concentrations within the linear range of 0.1–50 nM. An outstanding selectivity toward Al(III) was demonstrated by the proposed nanoprobe in the presence of interfering cations. Kinetics was used to study the selectivity of nanoprobe, which indicated second-order kinetics, and the rate constant was very high. The activation energies of Al(III) were found to be the lowest compared to those of other interfering ions. The results of kinetics and thermodynamic study of Al(III) were compared to those of four other competing ions. The thermodynamic data reveal that the interaction best suited for Al(III) ion compared to other metal ions (Al(III) > Co(II) > Hg(II) > Cr(III) ≅ Cr(VI)). The lower detection limit of the proposed nanoprobe for Al(III) is 1 nM. The present method also holds practical applicability for real water samples.

Monolayer-Protected Gold Nanoparticles Functionalized with Halogen Bonding Capability─An Avenue for Molecular Detection Schemes

“…Literature reports on NP aggregation-based molecular detection schemes are dominated with the study of aqueous gold NP (Au-NP) systems typically involving either silver or gold cores whose surfaces are modified with various ligands such as citrate, − tiopronin, thioctic acid, and mercaptobenzoic acid. , In addition, aqueous systems of this nature are inherently attractive because the NPs feature strong SPB absorption, which is characteristic of well-spaced, independent NPs in solution, which shifts dramatically upon an aggregation event instigated by the presence of a molecule that is able to interact with two or more NPs. For these systems, the aggregation event is often colorimetric: red shifts of the SPB to longer wavelengths upon aggregation manifest as visible solution color changes (e.g., wine red to gray/blue or from pale yellow to brown for Au-NP and Ag-NP systems, respectively) .…”

“…NP-based aggregation schemes have been used as colorimetric assays targeting a range of biomedical, environmental, forensic, and food-related analytes. , The examples include detection of cancer biomarkers (e.g., sialic acid), pesticides (e.g., chlorothalonil), antibiotics (e.g., ofloxacin), toxic or disease-related metal cations (e.g., Ag 1+ , Al 3+ , and Hg 2+ ), ,, physiologically relevant cations (e.g., K 1+ ), , narcotics (e.g., codeine), explosives (e.g., trinitrotoluene, TNT), ,, and steroids (e.g., progesterone) . Additionally, a number of reports have explored using NP aggregation events for DNA detection .…”

Ultrasensitive and selective colorimetric and smartphone-based detection of arsenic ions in aqueous solution using alliin–chitosan–AgNPs

“…, zero-, first- and second-order models were evaluated for As 3+ . The linear forms of the zero-order, first-order and second-order kinetic models are as follows ( eqn (5)–(7) ): 38 [ A t ] = [ A 0 ] − k 0 t Ln([ A t ]/[ A 0 ]) = − k 1 t 1/[ A t ] = k 2 t + 1/[ A 0 ] where, [ A t ] is the absorbance at time t and [ A 0 ] is the absorbance at time t = 0. The k 0 , k 1 and k 2 are zero-order, first-order and second-order rate constant, respectively.…”

“…This indicates that the rate is solely dependent on one specic reactant in solution. 38 Practical application and interference study Four water samples were collected from tube wells in different locations of the Dhemaji and Lakhimpur district, Assam. India.…”