Down shifting luminescent Eu³⁺ doped Ba<inf>6</inf>Gd<inf>2</inf>W<inf>3</inf>O<inf>18</inf> perovskite Nanosensor for Cu²⁺ ions in drinking water and food samples

Abstract

Down shifting red luminescent Eu3+ doped Ba6Gd2W3O18 (BGWO: y mol Eu3+; y = 0.00, 0.03, 0.07, 0.10, 0.15) is synthesized for the first time by citrate sol–gel method as a novel fluorescent sensor for Cu2+ in drinking water and food samples. BGWO: y mol Eu3+ is characterized with nano-domain crystalline cubic perovskite structure. PL emission, lifetime measurements and CIE chromaticity coordinates diagram confirmed that BGWO: 0.10 mol Eu3+ has a strong pure red emission color with long lifetime. BGWO: 0.10 mol Eu3+ Nanosensor shows a quite selectivity and sensitivity towards copper ion in comparison to other studied metal ions. Copper sensitivity is studied by BGWO: 0.10 mol Eu3+ Photoluminescence (PL) quenching method. Stern-Volmer plot was achieved over the concentration 0.01 to 100 μM with correlation coefficient (R2) of 0.9894 and a detection limit of 0.138 μM. The sensing mechanism is discussed in detail. Optimized BGWO: 0.10 mol Eu3+ Nanosensor was applied for copper detection in drink water and food sample with high recovery value.