Issue 18, 2010
From the journal:

Journal of Materials Chemistry

Superparamagnetic fluorescent nickel–enzyme nanobioconjugates: synthesis and characterization of a novel multifunctional biological probe†

Pramod Kumar Verma,a   Anupam Giri,a   Nguyen T. K. Thanh,*bc   Le Duc Tung,b   Oindrila Mondal,d   Mrinal Pald  and  Samir Kumar Pal*a  

* Corresponding authors

a Unit for Nano Science & Technology, Department of Chemical, Biological & Macromolecular Sciences, S.N. Bose National Center for Basic Sciences, Block JD, Sector III, Salt Lake, India
E-mail: skpal@bose.res.in

b The Davy-Faraday Research Laboratory, The Royal Institution of Great Britain, 21 Albemarle Street, London, UK

c Department of Physics and Astronomy, University College London, Gower Street, London, UK
E-mail: ntk.thanh@ucl.ac.uk
Fax: + 44 (0) 207-629-3569
Tel: +44 (0) 207-491-6509

d Department of Physics, The University of Burdwan, Golapbag, West-Bengal, India

Abstract

We report, for the first time, the synthesis of superparamagnetic and fluorescent nickel (Ni) nanoparticles (consisting of a single material) directly conjugated to an enzyme, bovine pancreatic α-chymotrypsin (CHT), by chemical reduction in aqueous solution. The structural characterization of Ni–CHT nanobioconjugates was carried out using UV-VIS absorption/photoluminescence spectroscopy and high-resolution transmission electron microscopy. The temperature dependence of the magnetization M(T) taken in zero field cooling and field cooling conditions, exhibits the main features of superparamagnetism. Circular dichroism studies were performed to monitor the structural perturbation to the structure of the enzyme after conjugation with the nickel nanoparticles (Ni NPs). The functional integrity of the enzyme conjugated to the Ni NPs was investigated by monitoring the enzymatic activity of the Ni–CHT conjugates using UV-VIS absorption spectroscopy and comparison with the unbound enzyme under similar experimental conditions. To confirm the conjugation of Ni NPs to CHT, we carried out Förster resonance energy transfer (FRET) studies using a fluorescent probe, 4-nitrophenyl anthranilate (NPA), known to bind at the enzymatic active site of CHT, as the donor (D) and Ni-NP-bound CHT as the acceptor (A). Our studies also demonstrated that the FRET from the donor NPA to the acceptor Ni NPs in CHT can be monitored to follow the D–A distance and hence the protein structure during thermal unfolding. Such a multifunctional superparamagnetic, fluorescent and biologically active nanobioconjugate may be of relevance in nanoparticle-based diagnostic and therapeutic applications.

Graphical abstract: Superparamagnetic fluorescent nickel–enzyme nanobioconjugates: synthesis and characterization of a novel multifunctional biological probe

About
Cited by
Related
Download options Please wait...

Supplementary files

Article information

DOI
https://doi.org/10.1039/B925477C
Article type
Paper
Submitted
10 Dec 2009
Accepted
08 Feb 2010
First published
10 Mar 2010

J. Mater. Chem., 2010,20, 3722-3728

Permissions

Request permissions

Superparamagnetic fluorescent nickel–enzyme nanobioconjugates: synthesis and characterization of a novel multifunctional biological probe

P. K. Verma, A. Giri, N. T. K. Thanh, L. D. Tung, O. Mondal, M. Pal and S. K. Pal, J. Mater. Chem., 2010, 20, 3722 DOI: 10.1039/B925477C

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Spotlight

Advertisements