Chitosan: an integrative biomaterial for lab-on-a-chip device

Chitosan: an integrative biomaterial for lab-on-a-chip devices

S. T. Koev,†‡a P. H. Dykstra,†a X. Luo,b G. W. Rubloff,c W. E. Bentley,b G. F. Payneb and R. Ghodssi*a

Received 24th May 2010, Accepted 17th August 2010

DOI: 10.1039/c0lc00047g

Chitosan is a naturally derived polymer with applications in a variety of industrial and biomedical

fields. Recently, it has emerged as a promising material for biological functionalization of

microelectromechanical systems (bioMEMS). Due to its unique chemical properties and film forming

ability, chitosan serves as a matrix for the assembly of biomolecules, cells, nanoparticles, and other

substances. The addition of these components to bioMEMS devices enables them to perform functions

such as specific biorecognition, enzymatic catalysis, and controlled drug release. The chitosan film can

be integrated in the device by several methods compatible with standard microfabrication technology,

including solution casting, spin casting, electrodeposition, and nanoimprinting. This article surveys the

usage of chitosan in bioMEMS to date. We discuss the common methods for fabrication, modification,

and characterization of chitosan films, and we review a number of demonstrated chitosan-based

microdevices. We also highlight the advantages of chitosan over some other functionalization materials

for micro-scale devices.

1 Introduction

One of the main challenges in the development of miniaturized

sensors and systems for life science applications continues to be

the integration of biological components. These types of micro￾devices typically need to be functionalized with biomolecules

such as DNA, enzymes, or antibodies to operate with sufficient

specificity and sensitivity. However, the harsh fabrication tech￾niques and materials involved in traditional MEMS fabrication

are incompatible with the labile biological components.

Specialized materials and processes are needed to allow for

seamless integration of biology into microdevices. Several

approaches toward this goal have been demonstrated based on

the use of self-assembled monolayers or surface-immobilized

polymers.1,2 The polymer chitosan is one of the most promising

candidates for interfacing biology and microdevices, and it is the

subject of this review paper.

Chitosan is a polysaccharide derived from naturally occurring

chitin. Its unique properties make it attractive for many indus￾trial and biomedical applications. Due to its pH dependent

solubility, it forms stable films on various surfaces under neutral

and basic pH conditions. Its amine groups serve for covalent

a

Department of Electrical and Computer Engineering, Institute for Systems

Research (ISR), University of Maryland, College Park, MD, 20742, USA.

E-mail: [email protected]

b

Fischell Department of Bioengineering, Center for Biosystems Research,

University of Maryland, College Park, MD, 20742, USA

c

Department of Materials Science and Engineering, Institute for Systems

Research (ISR), University of Maryland, College Park, MD, 20742, USA

† These authors contributed equally to this work.

‡ Currently address: Center for Nanoscale Science and Technology,

NIST, Gaithersburg, MD, 20899, USA

S: T: Koev

Stephan Koev was born in Bul￾garia in 1981. He received a BS

degree in Electrical Engineering

from the US Naval Academy in

2004, and MS and PhD degrees

in Electrical Engineering from

the University of Maryland in

2007 and 2009, respectively. His

doctoral research was in the area

of MEMS for biomedical appli￾cations. His interests include

micro- and nano-fabrication,

integrated optics, bio-device

interfaces, and MEMS

metrology. Currently, he is

a postdoctoral research asso￾ciate with the Center for Nanoscale Science and Technology at the

National Institute of Standards and Technology, Gaithersburg,

MD, USA.

P: H: Dykstra

Peter Dykstra received his B.S.

and M.S. degrees in Electrical

Engineering from Bucknell

University in 2006 and the

University of Maryland in 2008,

respectively. He is currently

pursuing his Ph.D. in Electrical

Engineering while working at

the MEMS Sensors and Actua￾tors Lab (MSAL) at the

University of Maryland. His

master’s research involved the

use of the biopolymer chitosan in

a microfluidic biosensor while

his current research focuses on

an electrochemical microfluidic

DNA array for protein sensing. His research interests include

biological and chemical sensors, micro fabrication, microfluidics,

and electrochemistry.

3026 | Lab Chip, 2010, 10, 3026–3042 This journal is ª The Royal Society of Chemistry 2010

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