title: Highly Sensitive and Selective In-Situ SERS Detection of Pb(2+), Hg(2+), and Cd(2+) Using Nanoporous Membrane Functionalized with CNTs.
abstract: Porous Anodic Alumina (PAA) membrane was functionalized with CoFe2O4 nanoparticles and used as a substrate for the growing of very long helical-structured Carbon Nanotubes (CNTs) with a diameter less than 20 nm. The structures and morphologies of the fabricated nanostructures were characterized by field emission- scanning electron microscopy (FE-SEM), energy dispersive X-ray (EDX), and Raman spectroscopy. By uploading the CNTs on PAA, the characteristic Raman peaks of CNTs and PAA showed 4 and 3 times enhancement, respectively, which leads to more sensitive Surface-Enhanced Raman Spectroscopy (SERS) substrates. For comparison, PAA and CNTs/PAA arrays were used as SERS substrates for the detection of Hg(2+), Cd(2+), and Pb(2+). The proposed sensor demonstrated high sensitivity and selectivity between these heavy metal ions. CNTs/PAA sensor showed excellent selectivity toward Pb(2+) over other metal ions, where the enhancement factor is decreased from ~17 for Pb(2+) to ~12 for Hg(2+) and to ~4 for Cd(2+). Therefore, the proposed CNTs/PAA sensor can be used as a powerful tool for the determination of heavy metal ions in aqueous solutions.
authors.affiliation: Nanophotonics and Applications (NPA) Lab, Department of Physics, Faculty of Science, Beni-Suef University, Beni-Suef, 62514, Egypt.
authors.forename: Mohamed
authors.initials: M
authors.lastname: Shaban
authors.affiliation: Nanophotonics and Applications (NPA) Lab, Department of Physics, Faculty of Science, Beni-Suef University, Beni-Suef, 62514, Egypt.|Department of Environment and Health Research, the custodian of the two Holy Mosques Institute for Hajj and Umrah Research, Umm Al-Qura University, Makkah, P.O. Box(6287), Saudi Arabia.
authors.forename: A R
authors.initials: AR
authors.lastname: Galaly