Biomedical Engineering Reference
In-Depth Information
Chapter 4
Quantum Dot-Electrochemiluminescence-
Based Biosensing
Abstract
As newly developed inorganic materials, quantum dots (QDs) have
received considerable attention because of their unique nanorelated properties
including high quantum yield, simultaneous excitation with multiple fluorescence
colors, and electrochemical properties. This chapter presents a general descrip-
tion of the electrochemiluminescence (ECL) related to QDs and their analytical
application. QDs including Si nanopaticles, semiconductor nanocrystals (NCs) and
recent emerged novel QDs such as graphene QDs were discussed about their ECL
behaviors and mechanisms. By utilization of this excellent property, new develop-
ments and improvements of its application in DNA-based analysis are discussed.
Different types of QDs with different strategies for the DNA-biosensing construc-
tions were expatiated and compared in detail.
Keywords
Quantum dots • Electrochemiluminescence • Aptamer • Biosensor
In 2002, Bard et al. found that quantum dots (QDs) could generate light emission
during potential cycling or pulsing, which was called electrogenerated chemilu-
minescence (also known as electrochemiluminescence and abbreviated ECL)
[
1
,
2
]. ECL involves the generation of species at electrode surfaces that undergo
electron-transfer reactions to form excited states, and light-producing procedure
when the excited molecule decays to the ground state. It is the combination of
chemiluminescence (CL) and electrochemistry. It not only holds the advantages of
sensitivity and wide dynamic range inherent to conventional CL, but exhibits the
advantages of the electrochemical method such as the simplicity, facility. Since the
first detailed ECL investigations described by Hercules and Bard et al. in the mid-
1960s [
3
-
5
], ECL has now become a powerful analytical technique and has been
widely used in the areas of immunoassay [
6
-
10
], food and water testing [
11
,
12
],
biowarfare agent detection, [
13
,
14
] DNA and aptamer biosensor [
15
-
18
]. In this
chapter, the basic QDs ECL mechanisms and its application in DNA-based detec-
tion are discussed in detail.
