Surface plasmon resonance (SPR) sensor integrated with a novel sensor film for early detection of dengue virus has been proposed to stop the dengue outbreak. Four types of sensor film, i.e. Au/Fe-NCC-CTAB/IgM, Au/CdSQDs-RGO/IgM, Au/CdSQDs-PAMAM/IgM, and Au/DSU/RGO-PAMAM/IgM were evaluated for different concentration of dengue virus envelope proteins (DENV-2 E-proteins). Out of these, Au/DSU/RGO-PAMAM/IgM sensor film was found to be a very effective sensor film due to the lowest quantitation limit and strongest binding affinity. Further, the Au/DSU/RGO-PAMAM/IgM sensor film was optimized to improve the detection sensitivity. The excellent sensitivity and binding affinity obtained were 333.896 °/nM and 9.345 TM-1, respectively. The other sensing parameters such as full-width-half-maximum, detection accuracy, and figure of merit were successfully measured at 0.00008 nM (0.8 fM) of DENV E-proteins concentration, indicating the best concentration limit obtained so far in 8 minutes of time detection. In the selectivity study, this sensor film was able to differentiate DENV-2 E-proteins in the mixture of competing analytes. The obtained recoveries from spiked bovine serum albumin are between acceptable recovery of 80-120%. The studies from Fourier-transform infrared (FTIR) spectroscopy, Ultraviolet-visible near-infrared (UV-Vis-NIR) spectroscopy, and Atomic force microscopy (AFM) confirmed the presence of functional groups, absorption band shifts, and increased in surface roughness values from 1.56 nm to 3.19 nm due to the binding event of sensing layer to DENV E-proteins. Taken these together, the integrated Au/DSU/RGO-PAMAM/IgM sensor film with SPR sensor has high potential as a dengue point-of-care diagnostic for screening the presence of dengue virus in asymptomatic blood donors.
*Summary of the thesis (Doctor of Philosophy) by Nuralia Sheh Omar.
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Date of Input: 29/04/2020 | Updated: 29/04/2020 | nursyahirah
Institute of Advanced Technology,
Universiti Putra Malaysia,
Selangor Darul Ehsan Malaysia