A water-soluble conjugated polyelectrolyte for selective and sensitive detection of carcinogenic chromium(VI)

Arvin Sain Tanwar; Mst Nasima Khatun; Moirangthem Anita Chanu; Tapashi Sarmah; Yeon-Ho Im; Parameswar Krishnan Iyer

doi:10.1039/d3an01387a

A water-soluble conjugated polyelectrolyte for selective and sensitive detection of carcinogenic chromium(VI)

Analyst. 2023 Nov 20;148(23):6011-6019. doi: 10.1039/d3an01387a.

Authors

Arvin Sain Tanwar^{1

2}, Mst Nasima Khatun¹, Moirangthem Anita Chanu¹, Tapashi Sarmah¹, Yeon-Ho Im², Parameswar Krishnan Iyer^{1

3}

Affiliations

¹ Department of Chemistry, Indian Institute of Technology Guwahati, Guwahati 781 039, India.
² School of Semiconductor and Chemical Engineering, Clean Energy Research Center, Jeonbuk National University, Jeonju, Jeonbuk 54896, Republic of Korea.
³ Centre of Nanotechnology and School for Health Science and Technology, Indian Institute of Technology Guwahati, Guwahati 781 039, India. pki@iitg.ac.in.

PMID: 37882495
DOI: 10.1039/d3an01387a

Abstract

Environmental water pollution caused by hexavalent chromium (Cr(VI)) is a threat to living beings due to its carcinogenic nature. Herein, we report the synthesis of a highly fluorescent water-soluble conjugated polyelectrolyte PPMI and its application as a fluorescence sensor to monitor traces of carcinogenic Cr(VI) ions in water. PPMI was synthesized via the oxidative polymerization method followed by post-polymer functionalization. Fluorescent PPMI exhibited a photoluminescence quantum yield of 23.87 and displayed a rapid, very selective, and sensitive turn-off fluorescence signal in response to Cr(VI), with a significantly high quenching constant of 1.32 × 10⁶ M^-1. The mechanism of sensing was found to be static quenching. The limit of detection of this highly accessible analytical method was found to be in nanomolar ranges, i.e. 0.85 nM. Additionally, sensing on solid platforms such as economical paper strips was successfully achieved, which is very challenging and highly recommended for any reliable, portable, and economical analytical method.