Detecting copper ions in aqueous solutions through interfacial potential modulation in liquid crystal-based sensors

doi:10.1016/j.microc.2025.114174

淡江大學機構典藏 > 理學院 > 化學學系暨研究所 > 期刊論文 > Item 987654321/127905

Please use this identifier to cite or link to this item: https://tkuir.lib.tku.edu.tw/dspace/handle/987654321/127905

Title:	Detecting copper ions in aqueous solutions through interfacial potential modulation in liquid crystal-based sensors
Authors:	Huang, Jhih-Wei;Chen, Chih-Hsin
Keywords:	Liquid crystal sensor;Copper ion detection;Zeta potential;Heavy metal sensing;5CB-imid
Date:	2025-06-02
Issue Date:	2025-09-22 12:07:25 (UTC+8)
Publisher:	Elsevier
Abstract:	This study introduces a novel liquid crystal (LC)-based sensor designed for copper ion detection by enhancing the potential at the LC/aqueous interface. The sensor employs an amphiphilic molecular probe, 2-(4′-pentyl-[1,1′-biphenyl]-4-yl)-4,5-dihydro-1H-imidazole (5CB-imid), doped into 4-cyano-4′-pentylbiphenyl (5CB) to create copper-selective LCs. At the LC/aqueous interface, the specific interaction between copper ions and 5CB-imid increases the interfacial potential, promoting a homeotropic orientation of the LCs and resulting in a distinct bright-to-dark transition in the optical signal. Zeta potential measurements confirm the increase in surface potential upon copper ion binding, and X-ray photoelectron spectroscopy verifies the presence of copper ions at the interface, supporting the proposed detection mechanism. The sensor achieves a lowest detectable concentration of 5 μM, well below the U.S. EPA’s permissible limit of 20 μM for drinking water and exhibits high selectivity, as it does not interact with other common divalent ions. Unlike other optical sensors, this LC-based system operates without the need for sample pre-mixing, making it highly practical for on-site applications. Its effectiveness was further validated through successful detection of copper ions in wastewater samples from an electroplating factory, showing reliable performance comparable to atomic absorption spectroscopy. Overall, this LC-based sensor offers a sensitive, selective, and efficient approach for environmental monitoring of copper ion contamination in industrial wastewater.
Relation:	Microchemical Journal 215, p.114174
DOI:	10.1016/j.microc.2025.114174
Appears in Collections:	[化學學系暨研究所] 期刊論文

Files in This Item:

File	Description	Size	Format
index.html		0Kb	HTML	156	View/Open

Loading...