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Protein‐Directed Synthesis of NIR‐Emitting, Tunable HgS Quantum Dots and their Applications in Metal‐Ion Sensing
Author(s) -
Goswami Nirmal,
Giri Anupam,
Kar Shantimoy,
Bootharaju Megalamane Siddaramappa,
John Robin,
Xavier Paulrajpillai Lourdu,
Pradeep Thalappil,
Pal Samir Kumar
Publication year - 2012
Publication title -
small
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.785
H-Index - 236
eISSN - 1613-6829
pISSN - 1613-6810
DOI - 10.1002/smll.201200760
Subject(s) - quantum dot , luminescence , spectroscopy , x ray photoelectron spectroscopy , materials science , raman spectroscopy , photochemistry , fourier transform infrared spectroscopy , quenching (fluorescence) , quantum yield , sulfide , analytical chemistry (journal) , chemistry , fluorescence , nanotechnology , optoelectronics , chemical engineering , organic chemistry , optics , engineering , physics , quantum mechanics , metallurgy
The development of luminescent mercury sulfide quantum dots (HgS QDs) through the bio‐mineralization process has remained unexplored. Herein, a simple, two‐step route for the synthesis of HgS quantum dots in bovine serum albumin (BSA) is reported. The QDs are characterized by UV–vis spectroscopy, Fourier transform infrared (FT‐IR) spectroscopy, luminescence, Raman spectroscopy, transmission electron microscopy (TEM), X‐ray photoelectron spectroscopy (XPS), circular dichroism (CD), energy dispersive X‐ray analysis (EDX), and picosecond‐resolved optical spectroscopy. Formation of various sizes of QDs is observed by modifying the conditions suitably. The QDs also show tunable luminescence over the 680–800 nm spectral regions, with a quantum yield of 4–5%. The as‐prepared QDs can serve as selective sensor materials for Hg(II) and Cu(II), based on selective luminescence quenching. The quenching mechanism is found to be based on Dexter energy transfer and photoinduced electron transfer for Hg(II) and Cu(II), respectively. The simple synthesis route of protein‐capped HgS QDs would provide additional impetus to explore applications for these materials.