title: Peptide-based fluorescence biosensors for detection/measurement of nanoparticles.
abstract: The ability to detect and quantify nanoparticles is essential but there is currently no simple, sensitive, and rapid method for the detection of nanomaterials. We have developed a novel peptide-based fluorescence-based biosensor for detection and measurement of negatively charged engineered nanoparticles (ENPs). A peptide biosensor (seven lysine residues linked to a cysteine through a three glycine residue linker) with attached fluorescent probes-fluorescein-5-maleimide (F5M) and tetramethylrhodamine-5-maleimide (TMR5M)-was constructed. The fluorescent probes allow close monitoring of the molecular interaction of the labeled peptide with ENPs. The ENP-peptide interaction induces the formation of agglomerates that can be detected and measured by changes in the fluorescence intensities of the labeled peptides or/and by differential light scattering. The relative fluorescence intensities of F5M and TMR5M decreased in a concentration-dependent manner on interaction with various types of negatively charged ENPs (ZnO, Fe3O4, CeO, and single-walled carbon nanotubes). Differential light scattering measurements also showed increases in the hydrodynamic size of the complex. The interactions were not affected by the pH of aqueous media, where humic acid (1 μg/mL) quenched the fluorescence intensity of F5M by approximately 25 %, whereas that of TMR5M was completely quenched. Interference by humic acid at lower concentrations was less prevalent. This novel method is a simple, rapid, and inexpensive in situ assay that shows promise as a primary-level testing technique for detection of ENPs in environmental samples. Graphical Abstract Detection of nanomaterials in aqueous solutions using fluorescently-labeled designer peptides.
authors.affiliation: Department of Biological Sciences, Faculty of Science, University of Alberta, Z512 Biological Sciences Building, 11455 Saskatchewan Drive, Edmonton, AB, T6G 2E9, Canada.|Clinical Chemistry Unit, Department of Medical Laboratory Science, Faculty of Basic Medical Sciences, College of Medicine of the University of Lagos, PMB 12003, Idi-Araba, Lagos, 100254, Nigeria.
authors.forename: Oluyemi
authors.initials: O
authors.lastname: Akinloye
authors.affiliation: National Institute for Nanotechnology, 11421 Saskatchewan Drive, Edmonton, AB, T6G 2M9, Canada.
authors.forename: Ramanarayan
authors.initials: R
authors.lastname: Krishnamurthy
authors.affiliation: Department of Biological Sciences, Faculty of Science, University of Alberta, Z512 Biological Sciences Building, 11455 Saskatchewan Drive, Edmonton, AB, T6G 2E9, Canada.|National Institute for Nanotechnology, 11421 Saskatchewan Drive, Edmonton, AB, T6G 2M9, Canada.
authors.forename: David
authors.initials: D
authors.lastname: Wishart
authors.affiliation: Department of Biological Sciences, Faculty of Science, University of Alberta, Z512 Biological Sciences Building, 11455 Saskatchewan Drive, Edmonton, AB, T6G 2E9, Canada. greg.goss@ualberta.ca.|National Institute for Nanotechnology, 11421 Saskatchewan Drive, Edmonton, AB, T6G 2M9, Canada. greg.goss@ualberta.ca.
authors.forename: Greg G
authors.initials: GG
authors.lastname: Goss
mesh_terms: D015374:Biosensing Techniques; D002851:Chromatography, High Pressure Liquid; D005456:Fluorescent Dyes / Q000737:chemistry*; D006812:Humic Substances; D053758:Nanoparticles / Q000032:analysis*; D010455:Peptides / Q000737:chemistry*
chemical_list: D005456:Fluorescent Dyes; D006812:Humic Substances; D010455:Peptides
keywords: Biosensor; Detection; Fluorescein; Measurement; Nanoparticles; Peptide