Quenching of the Photoluminescence of Gold Nanoclusters Synthesized by Pulsed Laser Ablation in Water upon Interaction with Toxic Metal Species in Aqueous Solution
Tahir,
Fernando Lazaro Freire Jr,
Ricardo Q. Aucelio,
Marco Cremona,
Juliana da S. Padilha,
Giancarlo Margheri,
Quaid Zaman,
Guilherme C. Concas,
Mariana Gisbert,
Sajjad Ali,
Carlos A. T. Toloza,
Yordy E. Licea,
Tatiana D. Saint’Pierre,
Rafael S. Carvalho,
Rajwali Khan,
Gino Mariotto,
Nicola Daldosso,
Geronimo Perez,
Tommaso Del Rosso
Affiliations
Tahir
Department of Physics, Pontifícia Universidade Católica do Rio de Janeiro, Rua Marques de São Vicente, Rio de Janeiro 22451-900, RJ, Brazil
Fernando Lazaro Freire Jr
Department of Physics, Pontifícia Universidade Católica do Rio de Janeiro, Rua Marques de São Vicente, Rio de Janeiro 22451-900, RJ, Brazil
Ricardo Q. Aucelio
Department of Chemistry, Pontifícia Universidade Católica do Rio de Janeiro, Rua Marques de São Vicente, Rio de Janeiro 22451-900, RJ, Brazil
Marco Cremona
Department of Physics, Pontifícia Universidade Católica do Rio de Janeiro, Rua Marques de São Vicente, Rio de Janeiro 22451-900, RJ, Brazil
Juliana da S. Padilha
Department of Chemistry, Pontifícia Universidade Católica do Rio de Janeiro, Rua Marques de São Vicente, Rio de Janeiro 22451-900, RJ, Brazil
Giancarlo Margheri
CNR—National Research Council of Italy—Istituto dei Sistemi Complessi, Via Madonna del Piano 10, 50019 Sesto Fiorentino, Italy
Quaid Zaman
Department of Physics, Pontifícia Universidade Católica do Rio de Janeiro, Rua Marques de São Vicente, Rio de Janeiro 22451-900, RJ, Brazil
Guilherme C. Concas
Department of Physics, Pontifícia Universidade Católica do Rio de Janeiro, Rua Marques de São Vicente, Rio de Janeiro 22451-900, RJ, Brazil
Mariana Gisbert
Department of Physics, Pontifícia Universidade Católica do Rio de Janeiro, Rua Marques de São Vicente, Rio de Janeiro 22451-900, RJ, Brazil
Sajjad Ali
Yangtze Delta Region Institute (Huzhou), University of Electronic Science and Technology of China, Huzhou 313001, China
Carlos A. T. Toloza
Department of Chemistry, Pontifícia Universidade Católica do Rio de Janeiro, Rua Marques de São Vicente, Rio de Janeiro 22451-900, RJ, Brazil
Yordy E. Licea
Centro Brasileiro de Pesquisas Físicas (CBPF), COMAN/CBPF, Rua Dr. Xavier Sigaud, 150, Urca, Rio de Janeiro 22290-180, RJ, Brazil
Tatiana D. Saint’Pierre
Department of Chemistry, Pontifícia Universidade Católica do Rio de Janeiro, Rua Marques de São Vicente, Rio de Janeiro 22451-900, RJ, Brazil
Rafael S. Carvalho
Department of Physics, Pontifícia Universidade Católica do Rio de Janeiro, Rua Marques de São Vicente, Rio de Janeiro 22451-900, RJ, Brazil
Rajwali Khan
Department of Physics, University of Lakki Marwat, Lakki Marwat 28420, Pakistan
Gino Mariotto
Department of Informatics, Università di Verona, Strada le Grazie 15, I-37134 Verona, Italy
Nicola Daldosso
Department of Informatics, Università di Verona, Strada le Grazie 15, I-37134 Verona, Italy
Geronimo Perez
Department of Mechanical Engineering, Universidade Federal Fluminense, Rua Passo da Patrias, 156, Niteroi, Rio de Janeiro 24210-240, RJ, Brazil
Tommaso Del Rosso
Department of Physics, Pontifícia Universidade Católica do Rio de Janeiro, Rua Marques de São Vicente, Rio de Janeiro 22451-900, RJ, Brazil
Sensors for the detection of heavy metal ions in water are in high demand due to the danger they pose to both the environment and human health. Among their possible detection approaches, modulation of the photoluminescence of gold nanoclusters (AuNCs) is gaining wide interest as an alternative to classical analytical methods based on complex and high-cost instrumentation. In the present work, luminescent oxidized AuNCs emitting in both ultraviolet (UV) and visible (blue) regions were synthesized by pulsed laser ablation of a gold target in NaOH aqueous solution, followed by different bleaching processes. High-resolution electron microscopy and energy-dispersive X-ray scattering confirmed the presence of oxygen and gold in the transparent photoluminescent clusters, with an average diameter of about 3 nm. The potentialities of the bleached AuNCs colloidal dispersions for the detection of heavy metal ions were studied by evaluating the variation in photoluminescence in the presence of Cd2+, Pb2+, Hg2+ and CH3Hg+ ions. Different responses were observed in the UV and visible (blue) spectral regions. The intensity of blue emission decreased (no more than 10%) and saturated at concentrations higher than 20 ppb for all the heavy metal ions tested. In contrast, the UV band emission was remarkably affected in the presence of Hg2+ ions, thus leading to signal variations for concentrations well beyond 20 ppb (the concentration at which saturation occurs for other ions). The limit of detection for Hg2+ is about 3 ppb (15 nmol/L), and the photoluminescence intensity diminishes linearly by about 75% up to 600 ppb. The results are interpreted based on the ligand-free interaction, i.e., the metallophilic bonding formation of Hg2+ and Au+ oxide present on the surface of the UV-emitting nanoclusters.
