title: Hydrophilic silver nanoparticles with tunable optical properties: application for the detection of heavy metals in water.
abstract: Due their excellent chemo-physical properties and ability to exhibit surface plasmon resonance, silver nanoparticles (AgNPs) have become a material of choice in various applications, such as nanosensors, electronic devices, nanobiotechnology and nanomedicine. In particular, from the environmental monitoring perspective, sensors based on silver nanoparticles are in great demand because of their antibacterial and inexpensive synthetic method. In the present study, we synthesized AgNPs in water phase using silver nitrate as precursor molecules, hydrophilic thiol (3-mercapto-1-propanesulfonic acid sodium salt, 3MPS) and sodium borohydride as capping and reducing agents, respectively. The AgNPs were characterized using techniques such as surface plasmon resonance (SPR) spectroscopy, dynamic light scattering (DLS), zeta potential (ζ-potential) measurements and scanning tunneling microscopy (STM). Further, to demonstrate the environmental application of our AgNPs, we also applied them for heavy metal sensing by detecting visible color modification due to SPR spectral changes. We found that these negatively charged AgNPs show good response to nickel (II) and presented good sensibility properties for the detection of low amount of ions in water in the working range of 1.0-0.1 ppm.
authors.affiliation: Department of Industrial Engineering, INSTM and CIMeR, University of Rome Tor Vergata, Rome, V. del Politecnico 1, 00133, Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Prosposito
authors.affiliation: Department of Industrial Engineering, INSTM and CIMeR, University of Rome Tor Vergata, Rome, V. del Politecnico 1, 00133, Italy.
authors.forename: Federico
authors.initials: F
authors.lastname: Mochi
authors.affiliation: Department of Industrial Engineering, INSTM and CIMeR, University of Rome Tor Vergata, Rome, V. del Politecnico 1, 00133, Italy.
authors.forename: Erica
authors.initials: E
authors.lastname: Ciotta
authors.affiliation: Department of Industrial Engineering, INSTM and CIMeR, University of Rome Tor Vergata, Rome, V. del Politecnico 1, 00133, Italy.
authors.forename: Mauro
authors.initials: M
authors.lastname: Casalboni
authors.affiliation: Department of Industrial Engineering, INSTM and CIMeR, University of Rome Tor Vergata, Rome, V. del Politecnico 1, 00133, Italy.
authors.forename: Fabio
authors.initials: F
authors.lastname: De Matteis
authors.affiliation: Department of Chemistry, University of Rome Sapienza, Rome, P.le A. Moro 5, 00187, Italy.
authors.forename: Iole
authors.initials: I
authors.lastname: Venditti
authors.affiliation: Department of Chemistry, University of Rome Sapienza, Rome, P.le A. Moro 5, 00187, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Fontana
authors.affiliation: Department of Chemistry, University of Rome Sapienza, Rome, P.le A. Moro 5, 00187, Italy.
authors.forename: Giovanna
authors.initials: G
authors.lastname: Testa
authors.affiliation: Department of Chemistry, University of Rome Sapienza, Rome, P.le A. Moro 5, 00187, Italy.
authors.forename: Ilaria
authors.initials: I
authors.lastname: Fratoddi
keywords: heavy metal sensor; nickel (II); optical materials; optical sensors; silver nanoparticles