An Integrated Screen-Printed Potentiometric Strip for Determination of Ca²⁺ in Seawater

Abstract

The detection of Ca 2+ in seawater is of critical importance to understand the growth of marine organisms and the circulation of the ocean ecosystem. This paper reports an integrated screen-printed potentiometric strip based on an all-solid-state Ca 2+ -selective polymeric membrane indicator electrode and an all-solid-state reference electrode for determination of Ca 2+ in seawater, for which the conductive carbon ink-based substrate was pretreated by the physical and electrochemical methods. The proposed pretreatment procedures are found to improve the electro-transfer kinetics, decrease the electron-transfer resistances and increase the double layer capacitance of the screen-printed carbon electrode, which are favorable for constructing the all-solid-state Ca 2+ -ISEs without the additional materials as solid contacts. The proposed screen-printed potentiometric strip shows a stable linear potential response in the range of 1.0 × 10 −5 − 0.1 M with a slope of 26.7 ±1.3 mV/dec (n = 3) in the presence of 0.5 M NaCl. Additionally, the prepared potentiometric strip was used to investigate the vertical distributions of Ca 2+ in seawater, and the results are consistent with those by inductively coupled plasma-optical emission spectrometry. This work indicates that the proposed potentiometric strip can be used as an alternative tool for on-site and rapid detection of Ca 2+ for marine monitoring.

A Review of Nanocomposite-Modified Electrochemical Sensors for Water Quality Monitoring

“…An example is an integrated Ca 2+ potentiometric strip for which electrochemical and physical techniques previously treat the conductive carbon ink-based ceramic substrate. Potentiometric and electrochemical performances strip have been investigated in seawater [ 160 ]. Potentiometric Ca 2+ determination using screen-printed ASS sensors can be an advantageous alternative with interesting accuracy and precision compared to conventional chromatography and photometric techniques.…”

Translating potentiometric detection into non-enzymatic amperometric measurement of H2O2

“…As shown in Fig. 4d, the amperometric signal is not influenced by the addition of NaCl, which may be attributed to the excellent selectivity toward Na + for the Ca 2+selective membrane [32]. Additionally, the reversibility for the amperometric signal readout based on H 2 O 2 for the GC/OMC/Ca 2+ -ISE was also investigated through the dilution method (Fig.…”

All-Solid-State Potentiometric Ion-Sensors Based on Tailored Imprinted Polymers for Pholcodine Determination

“…Screen-printing technology is an advanced method of manufacturing cost-effective, compact, and portable monitoring analytical devices for on-site analysis [ 31 , 32 , 33 ]. All-solid-state potentiometric-sensing electrodes have been extensively used in the determination of different ionic species because of their high reliability, good durability, and simple operation [ 34 , 35 , 36 , 37 , 38 ].…”