Non-equilibrium potentiometric sensors integrated with metal modified paper-based microfluidic solution sampling substrates for determination of heavy metals in complex environmental samples

Rochelle Silva; Ashiq Ahamed; Yi Heng Cheong; Ke Zhao; Ruiyu Ding; Grzegorz Lisak

doi:10.1016/j.aca.2022.339495

Non-equilibrium potentiometric sensors integrated with metal modified paper-based microfluidic solution sampling substrates for determination of heavy metals in complex environmental samples

Anal Chim Acta. 2022 Mar 8:1197:339495. doi: 10.1016/j.aca.2022.339495. Epub 2022 Jan 13.

Authors

Rochelle Silva¹, Ashiq Ahamed², Yi Heng Cheong³, Ke Zhao⁴, Ruiyu Ding⁴, Grzegorz Lisak⁵

Affiliations

¹ Interdisciplinary Graduate Programme, Nanyang Technological University, 61 Nanyang Drive, Academic Block North, Singapore, 637335, Singapore; Nanyang Environment and Water Research Institute, Residues and Resource Reclamation Center, 1 Cleantech Loop, Cleantech, Singapore, 637141, Singapore.
² Nanyang Environment and Water Research Institute, Residues and Resource Reclamation Center, 1 Cleantech Loop, Cleantech, Singapore, 637141, Singapore.
³ Nanyang Environment and Water Research Institute, Residues and Resource Reclamation Center, 1 Cleantech Loop, Cleantech, Singapore, 637141, Singapore; College of Engineering, School of Civil and Environmental Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore; Robert Bosch (South East Asia) Pte Ltd, 11 Bishan Street 21, 573943, Singapore.
⁴ Nanyang Environment and Water Research Institute, Residues and Resource Reclamation Center, 1 Cleantech Loop, Cleantech, Singapore, 637141, Singapore; College of Engineering, School of Civil and Environmental Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore.
⁵ Nanyang Environment and Water Research Institute, Residues and Resource Reclamation Center, 1 Cleantech Loop, Cleantech, Singapore, 637141, Singapore; College of Engineering, School of Civil and Environmental Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore. Electronic address: g.lisak@ntu.edu.sg.

PMID: 35168719
DOI: 10.1016/j.aca.2022.339495

Abstract

Metal modified paper-based substrates were utilized for microfluidic paper-based solution sampling coupled with Pb²⁺-ion selective electrodes (ISEs) with the aim of controlling the super-Nernstian response which usually occurs when using unmodified paper substrates. Potentiometric responses of Pb²⁺-ISEs coupled with gold, platinum and palladium coated paper substrates were investigated. Potentiometric response time was found to be predominantly dependent on the thickness of metallic layer deposited at the paper substrates. Paper-based substrates coated on both sides with 38 nm gold layers were found to be the most advantageous in controlling the super-Nernstian response of ISEs at non-equilibrium conditions. Durability studies indicated that the lifetime of Pb²⁺-ISEs could be doubled when used with paper-based substrates in complex environmental samples with high solid-to-liquid content. Determination of lead in real samples using metal modified paper substrates coupled with Pb²⁺-ISEs was validated by inductively coupled plasma optical emission spectrometry (ICP-OES). Detailed life cycle assessments were performed for model screen printed potentiometric sensors with and without metal modified paper-based solution sampling substrates. The results confirmed that the use of modified paper substrates demonstrated lower environmental impact per potentiometric measurement of Pb²⁺-ISE in prepared simulated environmental sample as compared to sensors without the use of paper substrates.

Keywords: Ion selective electrodes; Lead ion determination; Life cycle assessment of sensors; Microfluidic paper-based solution sampling; Potentiometric sensors.

MeSH terms

Ion-Selective Electrodes
Metals, Heavy*
Microfluidics*
Potentiometry

Substances

Metals, Heavy