Selective Discrimination of Toxic Polycyclic Aromatic Hydrocarbons in Water by Targeting π-Stacking Interactions

Abstract

The development of highly sensitive and selective devices for the rapid screening of polycyclic aromatic hydrocarbons (PAHs) in water is nowadays a crucial challenge owing to their alarming abundance in the environment and adverse health effects. Herein, inspired by the unique π-stacking interactions taking place between identical small aromatic molecules, a novel, generic and straightforward methodology to electrochemically determine and discriminate such pollutants is described. Such method is focused on covalently anchoring different PAHs on an Indium Tin Oxide (ITO) electrode surface by means of self-assembled monolayers (SAMs). The surface anchored PAHs act as recognition units to selectivity interact with a specific PAH target of the same nature. By tailoring the recognition platform with four different model PAH molecules (naphthalene, anthracene, pyrene and fluoranthene) and carrying out an electronic tongue approximation, the selective discrimination and quantification of the selected PAHs in aqueous samples at ultra-low concentrations was achieved impedimetrically, which was also validated using a certified reference PAH mixture.

3D-Printed COVID-19 immunosensors with electronic readout

“…All measurements were acquired per triplicate ( n=3 ) and represented with their corresponding standard deviation (SD) for reproducibility. A normalization procedure was carried out by means of Δ ratio (Δ ratio = ( R A – R 0 )/ R 0 , where R 0 and R A are the R CT values before and after incubating with an antigen/antibody mixture, respectively) in order to obtain independent and reproducible results while comparing the different electrodes used here [48] .…”

Synthetic Nanoarchitectonics of Functional Organic–Inorganic 2D Germanane Heterostructures via Click Chemistry

“…In this regard, the determination of carbon nanoparticles in water at low concentrations is becoming a challenging and emerging field due to their increasing production and use, which has led to concern over their release into the environment and their potential health and ecological risks. [ 55–57 ] For this goal, commercially available GQDs ($$\lambda _{{\rm{exc}}}^{{\rm{GQDs}}}$$ = 350 nm; $$\lambda _{{\rm{em}}}^{{\rm{GQDs}}}$$ = 436 nm) were used as model carbon nanoparticles because they can act as a fluorophore (donor) to transfer its excitation energy to the nearby CD@2D‐Ge chromophore (acceptor). This system has been carefully selected by following the FRET criteria: [ 58 ] i) the donor emission spectrum overlaps the acceptor absorption spectrum ($$\lambda _{{\rm{em}}}^{{\rm{GQDs}}}$$ ≈ $$\lambda _{{\rm{exc}}}^{{\rm{CD@2D - Ge}}}$$, see Figure S2b, Supporting Information) and ii) the close donor–acceptor pair distance is established through supramolecular π–π interactions by taking advantage of the sp 2 ‐like carbon skeleton nature of both GQDs and CDs.…”

Methodological Approaches for Monitoring Five Major Food Safety Hazards Affecting Food Production in the Galicia–Northern Portugal Euroregion

“…Electrochemical-based PAH sensors have been intensively developed in consideration of the relatively low cost, simplicity, and portability of the instrumentation, as recently reviewed by Comnea-Stancu et al [ 153 ]. Among the different measurable parameters, potentiometry, voltammetry, coulometry, electrical conductance/electrochemical impedance spectroscopy, and voltammetric methods have become the most popular [ 154 ].…”