Detection of Copper(II) in Water by Methylene Blue Derivatives

Abstract

Two novel phenothiazin‐5‐ium derivatives bearing cyclam moieties (3 a+ and 3 b+) were synthesized and investigated as Cu2+ sensors. Both ligands show intense spectral changes in the presence of Cu2+ in aqueous solutions. The high molar extinction coefficient of the chromophore allows both naked eye detection and spectrophotometric quantitative determination of the cation at a micromolar‐concentration scale. 3 a+ was found to outperform 3 b+, showing negligible spectral changes in the presence of excesses of other metal cations.

A dual-signal electrochemical immunosensor for the detection of HPV16 E6 oncoprotein based on PdBP dendritic ternary nanospheres and MBSi-Chi nanocomposites

“…1D, MB solution had characteristic absorption peaks at 612 nm and 663 nm (curve a). 31 MSN dispersion did not have any characteristic absorption peaks (curve b). The dispersion of MBSi-Chi nanocomposites also had two peaks (curve c), which were in accordance with the MB solution.…”

Small molecule sensors for the colorimetric detection of Copper(II): A review of the literature from 2010 to 2022

“…However the minimal color change from purple to faint purple at concentrations 10 -4 M-10 -5 M poses a problem in providing definitive detection of copper(II) at this concentration range. Sensors in this category contained the most sensors that were reported to solely detect copper(II) colorimetrically [101][102][103][104][105][106][107]. Other ions detected were I - [108] or CN - [109] colorimetrically and Zn 2+ [106] fluorometrically by the remaining sensors.…”

“…Other ions detected were I - [108] or CN - [109] colorimetrically and Zn 2+ [106] fluorometrically by the remaining sensors. In addition, three groups were able to synthesize and test their sensors in 100% fully aqueous buffer solutions with pH 4.75 and 7.0 [101,103,109].…”

“…Ciarrocchi et al [101] used phenothiazinium, commonly known as methylene blue (MB) dye, for its UV-Vis absorption properties, and cyclam, a common macrocyclic metal chelator, as the receptor for copper(II). Utilizing these two components, two derivatives were synthesized.…”

Colorimetric chemosensor for Cu(II) from electrospun nanofibrous mat mixed with 5‐methoxy‐salicylaldehyde azine

“…However, most of these studies were conducted in the solution phase. [17][18][19][20][21] Recently, research using chemosensing materials mixed with polymer-based solid supports was initiated due to an anticipated enhanced stability, the convenience of on-site analysis, easily usable platforms, ease of disposal and reversibility. [22][23][24][25][26][27][28][29] Practically, the solid nanomaterial capacity for adsorbing metal ions can establish the sensitivity and selectivity of the probes.…”