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Detection of Hg 2+ and F − Ions by Using Fluorescence Switching of Quantum Dots in an Au‐Cluster–CdTe QD Nanocomposite
Author(s) -
Paramanik Bipattaran,
Bhattacharyya Santanu,
Patra Amitava
Publication year - 2013
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201203576
Subject(s) - quantum dot , nanocomposite , analytical chemistry (journal) , cadmium telluride photovoltaics , ion , fluorescence , detection limit , materials science , fourier transform infrared spectroscopy , quenching (fluorescence) , chemistry , nanotechnology , physics , organic chemistry , quantum mechanics , chromatography
A single probe of an Au nanocluster–CdTe quantum dots nanocomposite has been developed by using tripeptide‐capped CdTe quantum dots (QD) and bovine serum albumin (BSA) protein‐conjugated Au 25 nanocluster (NC) for detection of both Hg 2+ ion and F − ion. The formation of Au‐NC–CdTe QD nanocomposite has been confirmed by TEM, steady state and time resolved spectroscopy, CD and FTIR studies. A significant signal off (74 % PL quenching at 553 nm) phenomenon of this nanocomposite is observed in presence of 6.56×10 −7 M Hg 2+ ion, due to salt‐induced aggregation. However, a dramatic PL enhancement (128 %) of the Au‐NC–CdTe QD nanocomposite is observed in presence of 8.47×10 −7 M F − anion. The calculated limit of detections (LOD) of Hg 2+ ion concentration and F − ion concentration are found to be 9 and 117 n M , respectively, which are within the safety range set by the United States Environment Protection Agency. Thus, the simple Au‐NC–CdTe QD optical‐based sensor is very useful to detect both toxic cations and anions.