title: Vanadium oxide nanoparticles as optical sensors of cysteine.
abstract: We report on the synthesis of vanadium oxide nanoparticles using the laser ablation in solution technique. The particles were characterized by dynamic light scattering-DLS, transmission electron microscopy-TEM, X-ray diffraction-XRD, X-ray photoelectron spectroscopy-XPS and UV-Vis optical spectroscopy. The oxide nanoparticles are mainly composed of tetragonal V2O5, a semiconductor with a 2.2 eV band gap. The interaction of the nanoparticles with cysteine, a very important aminoacid present in proteins, was studied. Upon reaction with cysteine, the bandgap of the nanoparticles shifts to the ultraviolet region at 2.87 eV. This color change from yellow to transparent can be used for selective cysteine sensing. Additionally, the intervalence band of the optical absorption spectra shows capability for cysteine sensing in the microM range.
authors.affiliation: Departamento de Física, Universidade Federal do Paraná, Centro Politécnico, Jardim das Américas, 81531-880 Curitiba, Paraná, Brazil.
authors.forename: W
authors.initials: W
authors.lastname: Celestino-Santos
authors.forename: A G Júnior
authors.initials: AG
authors.lastname: Bezerra
authors.forename: A B
authors.initials: AB
authors.lastname: Cezar
authors.forename: N
authors.initials: N
authors.lastname: Mattoso
authors.forename: W H
authors.initials: WH
authors.lastname: Schreiner
mesh_terms: D003545:Cysteine / Q000032:analysis / Q000737:chemistry*; D046529:Microscopy, Electron, Transmission; D053758:Nanoparticles / Q000737:chemistry*; D010316:Particle Size; D056951:Photoelectron Spectroscopy; D013056:Spectrophotometry, Ultraviolet; D013816:Thermodynamics; D017968:Vanadium Compounds / Q000737:chemistry*; D014961:X-Ray Diffraction
chemical_list: D017968:Vanadium Compounds; C066075:vanadium pentoxide; D003545:Cysteine