Fabrication of a Cu(II)-Selective Electrode in the Polyvinyl Chloride Matrix Utilizing Mechanochemically Synthesized Rhodamine 6g as an Ionophore

Abstract

A Cu(II)-selective electrode has been fabricated by utilizing a mechanochemically synthesized copper-specific ionophore “L” embedded in a poly(vinyl chloride) membrane. 2-Nitrophenyloctylether and sodium tetraphenylborate have been used as a plasticizer and as a solvent mediator, respectively, and found to be enhancing the sensitivity of the fabricated ion-selective electrode (ISE). A range of membranes (S1–S7) with varying compositions were casted and investigated in ISE. Results revealed an excellent Nernstian response of 29.38 ± 0.55 mV/dec for the ISE S6. The fabricated ISE operates well in the pH window 4.0–7.5, and the limit of detection was found to be 5 μM (0.3 ppm). Quick response time (15 s), long shelf-life, and selectivity (on the order of 10 –4 and 10 –5 ) over a number of interfering cations enabled S6 promising for real off laboratory sample analysis and can be employed to detect copper ion in various industrial as well as biological and environmental samples. To demonstrate the practical application of these ISE, the Cu concentration in the digested printed circuit board has been estimated using the standard calibration plot. The fabricated ISE has been regenerated through extracting copper by chelating with ethylenediaminetetraacetic acid.

Potentiometric Sensing

“…Paul et al fabricated a Cu 2+ -selective electrode utilizing an ionophore mechanochemically synthesized from rhodamine 6G hydrazide and tridentate zwitterion. 144 The described Cu 2+ -selective electrode exhibited a response slope of 29.3 mV/decade and a lower detection of 5 μM in the pH range from 3.0 to 7.5. The logarithmic selectivity coefficients over the main interfering ions, such as Pb 2+ , Zn 2+ , Ni 2+ , Co 2+ , Cd 2+ , and Fe 2+ , were above −3.0.…”

“…Paul et al fabricated a Cu 2+ -selective electrode utilizing an ionophore mechanochemically synthesized from rhodamine 6G hydrazide and tridentate zwitterion . The described Cu 2+ -selective electrode exhibited a response slope of 29.3 mV/decade and a lower detection of 5 μM in the pH range from 3.0 to 7.5.…”

Mechanochemical Synthesis of Organic Dyes and Fluorophores

“…The chemosensors worked well for Cu 2+ detection in filter paper strips as a part of on-field device application (Figure C). In another study, they prepared a previously reported chromophore ( 40 ) by hand-grinding a mixture of rhodamine 6G hydrazide ( 36 ) and a zwitterion ionophore ( 39 ) (Figure D) . This time, a 5 h reflux in methanol could be averted, and the product was obtained in just 5 min of grinding.…”

“…In another study, they prepared a previously reported chromophore (40) 41 by hand-grinding a mixture of rhodamine 6G hydrazide (36) and a zwitterion ionophore (39) (Figure 2D). 42 This time, a 5 h reflux in methanol could be averted, and the product was obtained in just 5 min of grinding. The chromophore was incorporated into a PVC matrix along with 2-nitrophenyloctyl ether (NPOE) as a plasticizer to fabricate an ion-selective electrode which is specific for Cu(II) ions.…”

Low-cost Pencil-Graphite Multi-electrodes for Simultaneous Detection of Iron and Copper

“…Due to the discharge of industrial effluents into natural waters, heavy metal ions adversely affect environment and human health (2). Among the heavy metals, Fe and Cu are the first and second most widely used industrial metals worldwide (3). Fe 3+ plays a significant role in various metabolic processes including oxygen transport, enzyme catalysis, DNA and RNA synthesis, and hemoglobin synthesis (4).…”