Detection and Determination of Released Ions in the Presence of Nanoparticles: Selectivity or Strategy?

Abstract

Metallic nanoparticles can release ionic species, but also both species can occur in the same samples. Therefore, there is a need of efficient and cost‐effective methods to determine these ionic species in the presence of the corresponding nanoparticles. Electroanalytical techniques open the door to this selective detection of NPs and their ions. In this work, a methodology that allows the direct determination of ionic silver (Ag+) in the presence of silver nanoparticles based on anodic stripping voltammetry was implemented. Silver nanoparticles were determined, after acidic digestion of the sample, by difference with respect to the total content of silver. The method was validated in terms of specific identification of silver ions, linearity, working range, limit of detection, limit of quantification, recovery, repeatability and ruggedness. All parameters are adequate for an analytical method following Eurachem recommendations. The validated method was used to determine the concentration of Ag+ and total silver in two commercial products of colloidal silver. The results were compared with those obtained by atomic absorption spectrometry in combination with an ultrafiltration step for isolation of ionic silver. There were no significant differences in the results. The proposed methodology benefits from the intrinsic selectivity of the electroanalysis methods, allowing to eliminate the steps of pretreatments of the samples, which are necessary in other techniques. The novelty of the article lies in the direct determination of Ag (I) ions in the presence of AgNPs, without the use of previous separation steps.

Detection, quantification, and characterization of polystyrene microplastics and adsorbed bisphenol A contaminant using electroanalytical techniques

“…The most common way to detect nanoparticles in electrochemical collision techniques is based on electroactive nanoparticles. Starting from very dilute solutions and using (ultra)microelectrodes, discrete current increases (spikes) are measured in the i-t curves (chronocoulometry) by applying the appropriate potential [ 6 , 19 ]. In more recent developments, electrocatalytic amplification, emulsion droplets, single bioparticles, photoelectrocatalysis, and blocking strategies have emerged [ 20 ].…”

Simultaneous Release of Silver Ions and 10–Undecenoic Acid from Silver Iron–Oxide Nanoparticles Impregnated Membranes

“…The operating current was set up at 2 mA, wavelength 248.3 nm and 0.2 nm spectral bandwidth for determining the iron content. For silver, the experimental parameters were 328.1 nm wavelength and 0.7 nm spectral bandwidth at an operating current of 5 mA [37,[40][41][42].…”

Recent advances in silver nanoparticle-based electrochemical sensors for determining organic pollutants in water: a review

“…Overall, AgNPs could be used as a catalyst in analyte-based electrochemical sensors or as a probe in modifier-based electrochemical sensors 124,[126][127][133][134][135][136][137][138][139][140][141] . Table 2 lists the recently reported AgNP-modified electrodes for detecting different organic analytes using different sensing mechanisms and transduction techniques.…”

“…The voltammetric signal amplification of MNP-based modifiers could be obtained by enriching the effect of MNPs without aggregating them. The signal amplification of AgNPs was studied to detect various analytes 134,137,141 . However, only a few studies reported the detection of organic pollutants based on AgNPs signal amplification.…”