title: An Interactive Quantum Dot and Carbon Dot Conjugate for pH-Sensitive and Ratiometric Cu2+Sensing.
abstract: Herein we report the photoinduced electron transfer from Mn2+-doped ZnS quantum dots (Qdots) to carbon dots (Cdots) in an aqueous dispersion. We also report that the electron transfer was observed for low pH values, at which the oppositely charged nanoparticles (NPs) interacted with each other. Conversely, at higher pH values the NPs were both negatively charged and thus not in contact with each other, so the electron transfer was absent. Steady-state and time-resolved photoluminescence studies revealed that interacting particle conjugates were responsible for the electron transfer. The phenomenon could be used to detect the presence of Cu2+ions, which preferentially, ratiometrically, and efficiently quenched the luminescence of the Qdots.
authors.affiliation: Department of Chemistry, Indian Institute of Technology Guwahati, Guwahati, 781039, Assam, India.
authors.forename: Kafeel
authors.initials: K
authors.lastname: Ahmad
authors.affiliation: Department of Chemistry, Gauhati University, Guwhati, Assam, India.
authors.forename: Sonit Kumar
authors.initials: SK
authors.lastname: Gogoi
authors.affiliation: Department of Chemistry, Indian Institute of Technology Guwahati, Guwahati, 781039, Assam, India.
authors.forename: Raihana
authors.initials: R
authors.lastname: Begum
authors.affiliation: Department of Chemistry, Indian Institute of Technology Guwahati, Guwahati, 781039, Assam, India.
authors.forename: Md Palashuddin
authors.initials: MP
authors.lastname: Sk
authors.affiliation: Department of Chemistry, Indian Institute of Technology Guwahati, Guwahati, 781039, Assam, India.
authors.forename: Anumita
authors.initials: A
authors.lastname: Paul
authors.affiliation: Department of Chemistry, Indian Institute of Technology Guwahati, Guwahati, 781039, Assam, India.|Centre for Nanotechnology, Indian Institute of Technology Guwahati, Guwahati, 781039, Assam, India.
authors.forename: Arun
authors.identifier: http://orcid.org/0000-0001-5095-6463
authors.initials: A
authors.lastname: Chattopadhyay
keywords: copper; electron transfer; electrostatic interactions; quantum dots; sensors