Synthesis and Computational Study of an Optical Fluorescent Sensor for Selective Detection of Ni2+ Ions

Maria Sadia; Jehangir Khan; Rizwan Khan; Syed Wadood Ali Shah; Adil Zada; Muhammad Zahoor; Riaz Ullah; Essam A Ali

doi:10.1021/acsomega.3c03131

Synthesis and Computational Study of an Optical Fluorescent Sensor for Selective Detection of Ni²⁺ Ions

ACS Omega. 2023 Jul 19;8(30):27500-27509. doi: 10.1021/acsomega.3c03131. eCollection 2023 Aug 1.

Authors

Maria Sadia¹, Jehangir Khan¹, Rizwan Khan², Syed Wadood Ali Shah³, Adil Zada¹, Muhammad Zahoor⁴, Riaz Ullah⁵, Essam A Ali⁶

Affiliations

¹ Department of Chemistry, University of Malakand, Chakdara 18800, Lower Dir, Khyber Pakhtunkhwa, Pakistan.
² Department of Electrical Engineering, Kwangwoon University, Seoul 54047, South Korea.
³ Department of Pharmacy, University of Malakand, Chakdara 18800, Lower Dir, Khyber Pakhtunkhwa, Pakistan.
⁴ Department of Biochemistry, University of Malakand, Chakdara 18800, Lower Dir, Khyber Pakhtunkhwa, Pakistan.
⁵ Department of Pharmacognosy, College of Pharmacy, King Saud University, Riyadh 11451, Saudi Arabia.
⁶ Department of Pharmaceutical Chemistry, College of Pharmacy King Saud University, Riyadh 11451, Saudi Arabia.

Abstract

The presence of an abnormal amount of Ni²⁺ in the human body causes various health issues. Therefore, this work aimed to synthesize the curcumin-based fluorescence-on sensor P [2,6-bis((E)-4-chlorobenzylidene)-cyclohexan-1-one] that was capable of selectively responding to Ni²⁺ ions in aqueous solution. The structure of P was confirmed by ¹H NMR and Fourier transform infrared (FTIR) spectroscopy. The Ni²⁺ ion sensing was based on the fluorescence enhancement of the fluorophore (P) in neutral aqueous medium. The response of the P-based sensor was highly selective toward Ni²⁺ ions, whereas the possible interferences from other metal cations were negligible. P had a fast response; it was selective and had a sensitive detection limit (LOD = 2 × 10^-10 M) toward Ni²⁺ ions in neutral medium with a high association constant (K) value of 3.6 × 10⁵ M^-2 for the complex formation between the P and Ni²⁺ ions. Job's plot and DFT calculations proved that the binding stoichiometry of P for Ni²⁺ was 2:1. P was recovered using EDTA as a chelating agent after being employed as a fluorescent sensor. These characteristics ensured the potential use of P as a new class of chemosensor for environmental applications.