Microchemical Journal 172 (2022) 106969 Available online 3 November 2021 0026-265X/© 2021 Elsevier B.V. All rights reserved. A fexible Eu:Y 2 O 3 -polyvinyl alcohol photoluminescent flm for sensitive and rapid detection of arsenic ions Arpita Dwivedi a , Monika Srivastava b , Rajnikant Upadhyay b , Amit Srivastava c , R.S. Yadav d , S. K. Srivastava a, * a Department of Physics, Institute of Science, Banaras Hindu University (BHU), Varanasi 221005, India b School of Materials Science and Technology, Indian Institute of Technology (BHU), Varanasi 221005, India c Department of Physics, TDPG College, VBS Purvanchal University, Jaunpur 222001, India d Department of Zoology, Banaras Hindu University, Varanasi 221005, India A R T I C L E INFO Keywords: Photoluminescence Nanophosphor Detection of As 3+ ions Real water sample PVA flm ABSTRACT The present article reports the synthesis and characterization of Eu:Y 2 O 3 nanophosphor (EYN) and EYN dispersed polyvinyl alcohol (PVA) fuorescent flm (EYF), with subsequent studies of sensing behavior for the detection of heavy metal ions particularly arsenic ions (As 3+ ) in real water samples. Various characterization techniques have been employed to confrm the successful phase formation/stability of EYF. The maximum emission peak for EYF with excitation wavelength 394 nm has been obtained as 612 nm and hence picked for the demonstration of PL (Photoluminescence) response with arsenic ions solution in natural pH range (at ~ 7 pH). Fluorescence in- tensities of EYF have been found to decrease quickly with As 3+ ion contents due to the reduction in the popu- lation of Eu 3+ ions in the 5 D 0 level and also due to formation of direct or indirect coordinate bonds with Eu 3+ . The PL intensity of the EYF nanoprobe has completely been quenched at 260 µg/L concentration of As 3+ ions with the limit of detection 57.5 ng/L (=0.057 ppb) for 0–100 µg/L linear range. The selectivity of EYF probe is also investigated for various common cations and ions present in real water samples. Moreover, sensing probe has been examined with different river water samples and shows recovery percent in between 98 and 105 & maximum % RSD value as 5.76 with n = 5 tests. Furthermore, the EYF sensing probe shows a visible color change with the contaminated water under UV–Vis light which useful for the onsite detection of arsenic concentration. Hence, EYF endows a promising pathway for a fexible, portable, low-cost sensing device for the sensitive and selective detection of arsenic ions in real water samples. 1. Introduction: In recent years, rapid advancements in industrialization, fast ur- banization, expanding mining operations have proliferated heavy metal pollution which severely threatens human health as well as the sur- rounding environment [1,2]. This critical issue has been of increasing signifcance and concern in the global context and thereby attracting rapid attention among researchers. Arsenic is known to be one of the venerable heavy metals and is widely distributed in free or compound forms in the earth’s crust. Depending upon the environmental condi- tions, arsenic exists in different oxidation states, such as 3 (arsine), 0 (arsenic), +3 (arsenite), and + 5 (arsenate), and can combine with other elements, inorganic and organic arsenicals [3,4]. In river water or groundwater (pH ~ 7.0), arsenic exists mainly in pentavalent (As 5+ ) and trivalent (As 3+ ) states as given in the inorganic hydrolysis species: H 3 AsO 3 , H 2 AsO 3 – , HAsO 3 2– , AsO 3 3– and H 3 AsO 4 , H 2 AsO 4 – , HAsO 4 2– , AsO 4 3– , respectively [5]. Arsenite (As 3+ ) is more poisonous than arse- nate (As 5+ ) and exists mostly in uncharged form H 3 AsO 3 , but with the increase in pH, gets dissociated into AsO(OH) 2 – to H 2 AsO 3 – forms [6]. Their direct and long-term exposure above a particular concentration result in nefarious effects including dermal changes, oxidative stress, severe cardiovascular and serious damage to the central nervous system, etc.[3,7]. In view of the above-mentioned detrimental effects of trace levels of arsenic, the US Environmental Protection Agency and World Health Organisation (WHO) have marked the contamination limit of arsenic in drinking water as low as 10 µg/L (~10 ppb) [2]. Abbreviations: EYN -, Eu:Y 2 O 3 nanophosphor; PVA -, Polyvinyl Alcohol; EYF -, Eu:Y 2 O 3 nanophosphor dispersed polyvinyl alcohol flm. * Corresponding author at: Department of Physics, Institute of Science, Banaras Hindu University (BHU), Varanasi 221005, India. E-mail address: sanjay_itbhu@bhu.ac.in (S.K. Srivastava). Contents lists available at ScienceDirect Microchemical Journal journal homepage: www.elsevier.com/locate/microc https://doi.org/10.1016/j.microc.2021.106969 Received 5 September 2021; Received in revised form 29 October 2021; Accepted 31 October 2021