Optical Materials 109 (2020) 110444 Available online 25 September 2020 0925-3467/© 2020 Elsevier B.V. All rights reserved. One-pot green synthesis of optical fuorescent sensor for selective detection of Ni 2+ ions and hydro gel studies J. Jone Celestina a , P. Tharmaraj a, * , C.D. Sheela b , L. Alphonse a , J. Shakina c a PG and Research Department of Chemistry, Thiagarajar College, Madurai, 625009, Tamilnadu, India b PG and Research Department of Chemistry, The American College, Madurai, 625002, Tamilnadu, India c Department of Chemistry and Research Centre, Sarah Tucker College, Palayamkottai, 627007, Tamilnadu, India A R T I C L E INFO Keywords: Anthracene schiff base Fluorescence sensor Nickel DFT ABSTRACT A Schiff base chemosensor derived from 2-aminophenol and 9-anthracenecarboxaldehyde (APAI) was designed and synthesized in a greener approach. It was prepared by microwave irradiation using few drops of acetic acid. The synthesized chemosensor was characterized by 1 H NMR and HR-LCMS mass analysis. Its excellent selectivity towards Ni 2+ was examined by both colorimetric and fuorometric sensing techniques. A rapid colour change from yellow to dark brown was observed when Ni 2+ was added. Among the employed metals only Ni 2+ has notable colour change. In the UV–Visible spectrum a new peak apart from the sensor appeared which confrms the selectivity in sensing. A signifcant enhancement in fuorescence was observed in presence of Ni 2+ . Among the various metals Cu 2+ , Co 2+ , Zn 2+ , Cr 3+ ,Mg 2+ , Hg 2+ , Fe 2+ , Fe 3+ , Cd 2+ , Pb 2+ Al 3+ , Pd 2+ , K + , Na + , Cr 2 O 4 2 investigated no major interference was observed even in higher concentration of analytes with a comparatively lowest detection limits of 0.04 μM. The experimental results are further supported by the DFT studies. The chemosensor is likely to fnd application in the recovery of contaminated water and hydrogel experiments were carried out in order to support the selective colorimetric detection of Ni 2+ by APAI. 1. Introduction Environmental pollution is caused mainly by the disability to degrade the heavy metal ions and the industrial waste [1]. Nickel being the most abundant element among the transition metals plays a vital role in many biological processes in our body [2–4]. Ni 2+ participates in respiration and in protein biosynthesis and its defciency affects both prokaryotic and eukaryotic organisms [5–9]. It is employed in dental prostheses and in magnetic tapes of computers [10]. However, surplus of Ni 2+ causes destructive effects to human health. Ni 2+ is released as in- dustrial pollutant by above said diverse industrial processes [11,12]. It tends to accumulate in kidney and blood thereby causing the roots of asthma, sinus and cancer in lungs on the other hand easy adsorption of Ni 2+ causes nasopharyngeal carcinoma [13].Hence, we are really in need for the development of a novel prototypical sensor for the selective sensing of Ni 2+ in environmental and biological samples [14–16]. Among the different types of chemosensors, Schiff base have drawn interests among chemists owing to their specifc isolation, low cost, easy detection and applicability in synthesis of chelating compounds, catal- ysis, optical properties [17–19]. They have the tendency to form stable chelating metal complexes due to effective electronic factors. The azo- methine bond (HC– – N) in the Schiff base has strong ability in rapid detection of metals. Many fuorescent sensors were developed over the past decade. Many examples such as, 5-chloro salicylaldehyde and 8-aminoquinoline were employed to develop sensors which selectively sensed Ni 2+ among the interfering metals [20]. Arene based Schiff bases sensed dual ions Zn 2+ and Ni 2+ . Hence it is much essential to develop a effcient sensor with high specifcity and sensitivity with many appli- cations [21]. The present work deals with development of potential Schiff base sensor from 2-amino phenol and 9-anthracene carboxaldeyde by microwave assisted synthesis and to study the fuorescent nature and optical property. The developed sensor was characterised by spectral analysis and Hydrogel experiment. 2. Experimental section 2.1. General information, chemicals, solvents and starting materials All the reagents, metal salts and solvents were Analytical grade (A.R. grade) and used without any further purifcation. High purity 2-Amino * Corresponding author. E-mail address: tharmaraj_chem@tcarts.in (P. Tharmaraj). Contents lists available at ScienceDirect Optical Materials journal homepage: http://www.elsevier.com/locate/optmat https://doi.org/10.1016/j.optmat.2020.110444 Received 23 July 2020; Received in revised form 11 September 2020; Accepted 14 September 2020