Rational design of a material for rapid colorimetric Fe2+ detection

Abstract

Wereport on the rational design of a novel TiO2 based screen-printed material suitable for sensitive and selective\ud detection of iron ions in water. This includes the synthesis and characterization of large mesoporous TiO2 nanostructures,\ud screen-printing of thick titania films on glass surfaces and their functionalization with 2,2′:6′,2″-\ud terpyridin-4′-ylphosphonic acid (terpy). The ultra-high affinity between iron ions and the TiO2-anchored terpy\ud receptor makes this system potentially applicable to the analysis of iron in environmental, food, biological, and\ud biomedical systems by a readily quantifiable colour change. Rapid (b30 s) colour change of the material from\ud white to magenta permits easy detection of as low as 0.3 ppm of Fe2+ by the naked eye. The intensity of the colour\ud change depends on the nature of the nanoparticles, the overall TiO2 film thickness, and the Fe2+ concentration.\ud The material was characterized using profilometry, diffuse reflectance UV–vis spectroscopy, and X-ray\ud photoelectron spectroscopy (XPS) before and after treatment with aqueous solutions of Fe2+. The designed material\ud shows colour reversibility upon treatment with EDTA solutions, which allows for multiple reuses of the\ud same film with no effect on sensitivity

Wearable Textile UHF-RFID Sensors: A Systematic Review

“…The general conductive ink is a metal-filled paste with a solid content of a certain percentage, for which the curing process under a required temperature by the screen machine is necessarily performed after the ink is pressed. Although the screen printing technique was invented in ancient China, this technique has been systematically developed in the last 20 years and is employed for the design of robust non-bendable chemical sensors [ 28 ], electrochromic materials [ 29 ], and non-bendable UHF-RFIDs [ 30 ]. However, the invention of conductive compositions for textile printing, described by Ujiie in 2006 [ 31 ] that was further developed by Cie in 2015 [ 32 ] opens the door for utilization of screen printing in flexible electronics.…”

Probing the Influence of Counter Electrode Structure on Electrochromic‐Device Operating Potentials and Performance Using Electrochemical Impedance Spectroscopy

“…Previously, it was demonstrated that 2,2':6',2''terpyridine (terpy) moiety can form stable complexes with a variety of metals in different oxidation states. [17][18] This moiety as a part of different ligands can be used to covalently anchor and grow electrochromic (EC) molecular wires on a flat surface [19][20] or to form EC coatings or separate nanosheets of metallo-supramolecular polymers. [21][22][23] Our group has developed ECDs that utilize just a monolayer of EC terpy-based metal complexes deposited on enhanced surface area conductive supports [24] to form the working electrode.…”

“…Among the others, ECDs based on polypyridine metal‐coordination complexes demonstrate enhanced cyclic stability, short switching times and exceptional coloration efficiency. Previously, it was demonstrated that 2,2′:6′,2′′‐terpyridine (terpy) moiety can form stable complexes with a variety of metals in different oxidation states [17–18] . This moiety as a part of different ligands can be used to covalently anchor and grow electrochromic (EC) molecular wires on a flat surface [19–20] or to form EC coatings or separate nanosheets of metallo‐supramolecular polymers [21–23] .…”

In-situ fabrication of reduced graphene oxide/leucomethylene blue/platinum nanoparticles modified electrode for voltammetric determination of trace Fe(II) in seawater

“…Since the concentration of iron in seawater is relatively low, it is a challenge to accurately measure the iron content during environmental analysis. Fe(II) can be detected by many methods such as spectrophotometry [9][10][11], fluorescence [12,13], phosphorescence [14], etc. Although these methods have serious of advantages, they are usually inconvenient, expensive, and time-consuming [15].…”