Environmental Engineering Reference
In-Depth Information
11.5.5 Detection of Small Molecules, Toxic Chemicals
and Drugs
The presence of large surface area to volume ratio, ability to reduce the
overpotentials of many electroanalytical reactions and the ability to maintain
reversibility of redox reaction have capacitated AuNPs for the application in
detecting small molecules, toxic chemicals and drugs. These molecules are present
in very minute amounts and the most common format of assay with AuNPs is
electrochemical assay. Wang et al. [
70
] have designed electrochemical assay using
self-assemble dithiothreitol(DTT)-dodecanethiol (DDT)-Au colloid modified
Au-electrode. This assay immensely improved the detection of epinephrine at the
Au electrode, with a detection limit of 60 nM. AuNPs are widely applied for the
detection of glucose [
71
,
72
], dopamine [
73
,
74
], uric acid [
75
,
76
], ascorbic acid
[
77
-
80
], bisphenol A [
81
] and nitrite [
82
].
Conclusions
With the above applications in the sensing technology, it was proved in many
instances that AuNP is the potential nanoparticle and play a pivotal role.
Further ahead, the production of various shapes and sizes of the AuNPs and
other Au-based nanostructures paved the way to generate a wide range of
higher sensitive sensing platforms. In addition, the tailor-made commercial
availability of AuNPs makes easier to end users. Apart from these, the visual
nature of AuNPs under microscopic analyses creates the faithful way of direct
visualization of the tiny bioanalytes conjugated AuNPs in the complex
mixture. With these sensing progress with AuNPs, there will be several
AuNP-based sensors created with interdisciplinary sciences with higher sen-
sitive and specificity.
Acknowledgements T.H. Tang was supported by a Universiti Sains Malaysia (USM) Research
Grant (Number: 1001/CIPPT/813043). Y. Chen was supported by UM.C/625/1/HIR/MOHE/
MED/16/5. T. Lakshmipriya was supported by the Research fellowship from USM.
References
1. Daniel MC, Astruc D (2004) Gold nanoparticles: assembly, supramolecular chemistry,
quantum-size-related properties, and applications toward biology, catalysis, and nanotechnol-
ogy. Chem Rev 104:293-346
2. Zayats M, Baron R, Popov I, Willner I (2005) Biocatalytic growth of Au nanoparticles: from
mechanistic aspects to biosensors design. Nano Lett 5:21-25
3. Haick HJ (2007) Chemical sensors based on molecularly modified metallic nanoparticles. J
Phys D Appl Phys 40:7173-7186
