Preparation of modified CdSe/ZnS quantum dots and gold nanoparticles for glucose and dengue detection
Development of sensors combined with nanomaterials becoming an interesting area due to their unique optical properties. In this research, two different biosensor utilizing CdSe/ZnS quantum dots (QDs) and gold nanoparticles (AuNPs) have been developed and successfully applied to detect glucose...
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| Main Author: | |
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| Format: | Thesis |
| Language: | English |
| Published: |
2018
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| Subjects: | |
| Online Access: | http://psasir.upm.edu.my/id/eprint/76889/1/ITMA%202018%2020%20-%20IR.pdf |
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| Summary: | Development of sensors combined with nanomaterials becoming an interesting area
due to their unique optical properties. In this research, two different biosensor
utilizing CdSe/ZnS quantum dots (QDs) and gold nanoparticles (AuNPs) have been
developed and successfully applied to detect glucose and dengue virus DNA,
respectively. CdSe/ZnS QDs is utilized in our first prepared biosensor for glucose
monitoring. The CdSe/ZnS QDs was successfully prepared via hot injection method
while the ZnS layer was made using the successive ionic layer adsorption and
reaction (SILAR) method. The prepared QDs was spherical monodisperse with
uniform sizes of 3 to 3.2 nm and 10 to 12 nm for CdSe core QDs and CdSe/ZnS
core-shells QDs, respectively. The prepared CdSe/ZnS QDs has been modified with
organic ligand for glucose analysis. Detection was performed using glucose
concentrations ranging from 0 to 40 mM with linear relationship was observed from
0 to 10 mM (with R2 = 0.9964) and limit of detection was obtained at 0.3 mM.
Comparison between our developed biosensor with commercialized assay kit result
in 99% similarity thus indicated that the developed biosensor utilizing CdSe/ZnS
QDs was reliable for the detection of glucose.
AuNPs is utilized in our second prepared biosensor for dengue virus detection.
Positively charged AuNPs was interacting with negatively charged PNA/DNA
hybridised biochip via electrostatic interaction and successfully used to detect
dengue virus using both naked eye and optical scanner. Detection of dengue virus
was study using concentration ranging from 10 pM to 1 μM with a detection limit
was obtained at 10 pM. Repeatability and reproducibility study gave relative
standard deviations (RSD) less than 5% in all measurements, which indicate that the
chips produced in this study are suitable for mass fabrication of devices with similar responses. Comparison study between our developed PNA/DNA biochip with real
time RT-PCR was investigated and obtaining 88% agreement.
Both scopes covered in this study give new possibilities for healthcare monitoring,
where these studies improved the specificity and selectivity of the developed biosensor. |
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