Germanium nanocrystals as luminescent probes for rapid, sensitive and label-free detection of Fe3+ions

• DOI: 10.1039/c4nr07470j
• Publication Date: 2015-02-24T16:21:31Z
• Authors: Darragh Carolan; Hugh Doyle
• Keywords: Fluorescent sensing platform; Germanium; 13. Climate action; 02 engineering and technology; Metal ions; European Commission; Sensitive detection; 0210 nano-technology; Highly luminescent; 01 natural sciences; Nanocrystals; 0104 chemical sciences

Luminescent water-soluble germanium nanocrystals (Ge NCs) have been developed as a fluorescent sensing platform for the highly selective and sensitive detection of Fe3+ via quenching their strong blue luminescence, without need analyte-specific labelling groups. The amine-terminated Ge NCs were separated into two discrete size fractions with average diameters 3.9±0.4 nm 6.8±1.8 using centrifugation. smaller 3.9 possessed an lifetime 6.1 ns quantum yield (QY) 21.5%, which is strongly influenced by solution pH. In contrast, 6.8 exhibited green luminescence longer 7.8 lower QY (6.2%) that insensitive to Sensitive was successfully demonstrated, linear relationship between concentration observed from 0-800 μM, limit 0.83 μM. show excellent selectivity toward ions, no fluorescence signal induced presence Fe2+ allowing phase discrimination ions same element different formal charges. mechanism confirmed static time-resolved photoluminescence spectroscopies, while applicability this assay in real water samples demonstrated.