title: Fluorescent sensor for Cr(VI) based in functionalized silicon quantum dots with dendrimers.
abstract: Highly luminescent nanoparticles based in Silicon quantum dots, coated by hydroxyl PAMAM dendrimer (PAMAM-OH) of 5th generation, were obtained by one step process by hydrothermal treatment of 3-Aminopropyl)triethoxysilane (APTES) in aqueous solution. Previous to the optimization of the synthesis procedure, different dendritic molecules of 5th generation were tested to obtain the most intense fluorescence signal. The influence of different parameters such ratio APTES/PAMAM-OH, pH and ionic strength on the fluorescence intensity was studied. The fluorescence spectra showed maximum excitation and emission wavelengths at 370 and 446 nm, respectively. The obtained silicon nanoparticles (SiQDs@PAMAM-OH) were characterized by TEM, DLS and XPS, and were found to detect selectively Cr(VI) in aqueous solutions at 2.7 μM level of detection, sensitivity of 0.2 μM with a RSD of 0.16% (n=10). To study the feasibility of the proposed system for Cr(VI) detection, it was tested in real electrochemical solution bath and a tanning effluent obtained from electrochemical industry and with two certified waters, demonstrating promising outcomes as nano-sensor.
authors.affiliation: Centro de Investigação em Q uímica, Departamento de Química e Bioquímica, Faculdade de Ciências da Universidade do Porto, Porto, Portugal.
authors.forename: B B
authors.initials: BB
authors.lastname: Campos
authors.affiliation: Departamento de Química Inorgánica, Facultad de Ciencias, Universidad de Málaga, Campus de Teatinos s/n, 29071 Málaga, Spain. Electronic address: malgarra67@gmail.com.
authors.forename: M
authors.initials: M
authors.lastname: Algarra
authors.affiliation: Departamento de Química Inorgánica, Universidad Autónoma de Madrid, Cantoblanco 28049, Madrid, Spain.
authors.forename: B
authors.initials: B
authors.lastname: Alonso
authors.affiliation: Departamento de Química Inorgánica, Universidad Autónoma de Madrid, Cantoblanco 28049, Madrid, Spain.
authors.forename: C M
authors.initials: CM
authors.lastname: Casado
authors.affiliation: Departamento de Química Inorgánica, Facultad de Ciencias, Universidad de Málaga, Campus de Teatinos s/n, 29071 Málaga, Spain.
authors.forename: J
authors.initials: J
authors.lastname: Jiménez-Jiménez
authors.affiliation: Departamento de Química Inorgánica, Facultad de Ciencias, Universidad de Málaga, Campus de Teatinos s/n, 29071 Málaga, Spain.
authors.forename: E
authors.initials: E
authors.lastname: Rodríguez-Castellón
authors.affiliation: Centro de Investigação em Q uímica, Departamento de Química e Bioquímica, Faculdade de Ciências da Universidade do Porto, Porto, Portugal.
authors.forename: J C G
authors.initials: JC
authors.lastname: Esteves da Silva
keywords: Chromate; Dendrimers; Fluorescent sensors; Silicon dots