Multi-coloration of Calixarene-coated Silver Nanoparticles for the Visual Discrimination of Metal Elements

Abstract

Upon mixing with metal ions such as Cd II , Tb III , Cu II , Ni II , Pb II , Zn II , and Co II at pH 10.0, solutions of silver nanoparticles (AgNPs) coated with calix[4]arene-p-tetrasulfonate (CAS-AgNP) exhibited multi-coloration from yellow to orange, violet, and green, depending on the metal elements present, which allowed for visual discrimination of the ions. This is contrary to the AgNP sensors exhibiting a uniform color change from yellow to red upon binding of a receptor molecules at the surface of AgNPs to an analyte. The TEM images of the samples obtained from the resultant solution showed two regions. First, a region where CAS-AgNPs assembled on the surface of the metal hydroxides. The size of the hydroxide crystals varied from 50 to 200 nm with the type of metal element present, and roughly correlated with the extinction band of the aggregated AgNPs. Second, the amorphous region in which CAS-AgNPs dispersed randomly. The difference in the amount of the crystal region and the area seemed to lead to the multi-coloration.

The Role of Calix[n]arenes and Pillar[n]arenes in the Design of Silver Nanoparticles: Self-Assembly and Application

“…Presence of additional binding sites also opens new opportunities towards forming cascade composite structures based on inorganic materials. p-Sulfonatocalix [4]arene CA-4-modified AgNPs were synthesized by interaction of AgNO 3 -calixarene mixture with NaBH 4 [41]. Solutions of nanoparticles obtained upon addition of metal ions at pH 10 have different colors.…”

Silver Nanoparticles with Sodium Dodecyl Sulfate as a Colorimetric Probe for the Detection of Dithiocarbamate Pesticides in Environmental Samples

“…To address the problems, new analytical technologies are emerging based on nanosized materials, especially silver and gold nanoparticles. Their unique physical and chemical properties have enabled the development of several analytical procedures for the analysis of metal ions, 14,15 environmental, food and biochemical interests. [16][17][18] Among the environmental samples, the determination of the pesticides and their residues on food samples are attracting considerable attention.…”

Detection of Tetracycline in Water Using Glutathione-protected Fluorescent Gold Nanoclusters

“…In the field of analysis, attention has increasingly turned to the fluorescence detection method in recent years because of the advantages of ease of operation, low cost, real-time detection, and high sensitivity. [15][16][17][18] Tc, with no fluorescence, was detected by a series of fluorescence sensors in the past few decades with the help of Eu 3+ -based nanoparticles, 19,20 metal-organic coordination polymers, 21,22 CdTe quantum dots, 23 and carbon quantum dots, 24 etc. Compared with these fluorescent probes, gold nanoclusters (AuNCs) have low toxicity with an ultra-small size (∼2 nm).…”