Earlier, we have reported the synthesis and thorough physicochemical characterization of AuQC@NLf, where NLf refers to native lactoferrin. In this paper, we show how the clusters are formed in the protein cavity as a function of time. MALDI MS of the protein samples measured as a function of time of incubation show the evolution of the clusters. The mechanism of cluster growth suggests metal ion transfer across molecules which require further study. Copyright © 2011 American Scientific Publishers All rights reserved.

Pradeep Thalappil

Department Of Chemistry

CLUSTER GROWTH

Function of time

GOLD CLUSTERS

ION TRANSFER

LACTOFERRIN

MALDI-MS

NANO-BIO INTERACTION

Physico-chemical characterization

PROTEIN CAVITY

PROTEIN SAMPLES

QUANTUM CLUSTERS

Luminescence

Metal ions

Proteins

Gold compounds

Gold

nanomaterial

article

electrospray

incubation time

matrix assisted laser desorption ionization time of flight mass spectrometry

molecular evolution

physical chemistry

protein analysis

PROTEIN CONTENT

Quantum chemistry

chemistry

Crystallization

materials testing

methodology

particle size

ultrastructure

LUMINESCENT MEASUREMENTS

Nanostructures

IIT Madras is a public technical and research university located in Chennai, Tamil Nadu. Founded in 1959, it is recognised as an Institute of National Importance.

IIT Madras has been ranked as the top engineering institute in India for four years in a row by the National Institutional Ranking Framework of the MHRD

It currently offers undergraduate, postgraduate and research degrees across 16 disciplines in Engineering, Sciences, Humanities and Management. About 596 faculty belonging to science and engineering departments and centres of the Institute are engaged in teaching, research and industrial consultancy.

IIT Madras

Journal of Biomedical Nanotechnology

We report the synthesis of highly luminescent, water soluble quantum clusters (QCs) of gold, which are stabilized by an iron binding transferrin family protein, lactoferrin (Lf). The synthesized AuQC@Lf clusters were characterized using UV-Visible spectroscopy, X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), photoluminescence (PL), matrix assisted laser desorption ionization mass spectrometry (MALDI-MS), FTIR spectroscopy and circular dichroism (CD) spectroscopy along with picosecond-resolved lifetime measurements. Detailed investigations with FTIR and CD spectroscopy have revealed changes in the secondary structure of the protein in the cluster. We have also studied Förster resonance energy transfer (FRET) occurring between the protein and the cluster. The ability of the clusters to sense cupric ions selectively at ppm concentrations was tested. The stability of clusters in widely varying pH conditions and their continued luminescence make it feasible for them to be used for intracellular imaging and molecular delivery, particularly in view of Lf protection. © 2010 The Royal Society of Chemistry.

Nanoscale

Luminescent quantum clusters of gold in transferrin family protein, lactoferrin exhibiting FRET

Size evolution of luminescent lactoferrin protected gold clusters

Journal	Journal of Biomedical Nanotechnology
ISSN	15507033
Open Access	No