Thien-Toan H Tran - Profile on Academia.edu (original) (raw)
Related Authors
Uploads
Papers by Thien-Toan H Tran
Carbon nanotubes and graphene nano field-effect transistor-based biosensors
TrAC Trends in Analytical Chemistry, 2015
Affinity chemiresistor sensor for sugars
Talanta, 2014
In this work, a non-enzymatic chemiresistive sugar sensor has been developed by combining a synth... more In this work, a non-enzymatic chemiresistive sugar sensor has been developed by combining a synthetic receptor with aligned single-walled carbon nanotubes (SWNTs) device. Briefly, boronic acid as a multivalent sugar receptor was immobilized on carbon nanotubes through amide bond formation. The interaction between three common sugars (d-glucose, d-fructose and sucrose) and boronic acid modified SWNTs device was studied. The effect of pH on the receptor-ligand binding was examined and highest response was observed at pH 9. The chemiresistive sensor exhibited specific and reproducible detection with sensitivity over the concentration range of 1-20mM, 1-25 mM, and 1-30 mM for fructose, glucose, and sucrose, respectively. The sensor showed no interference from common electroactive compounds such as citric acid, uric acid, and ascorbic acid. Furthermore, the sensor retained 97.4% of the initial value after five regeneration cycles with an acidic buffer at pH 5, thus ensuring good reusability.
Divalent mercuric (Hg 2+) ion and monomethyl mercury (CH 3 Hg +) are two forms of mercury that ar... more Divalent mercuric (Hg 2+) ion and monomethyl mercury (CH 3 Hg +) are two forms of mercury that are known to be highly toxic to humans. In this work, we present a highly selective, sensitive and label-free chemiresistive biosensor for the detection of both, Hg 2+ and CH 3 Hg + ions using DNA-functionalized single-walled carbon nanotubes (SWNTs). The SWNTs were functionalized with the capture oligo-nucleotide, polyT, using a linker molecule. The polyT was hybridized with polyA to form a polyT:polyA duplex. Upon exposure to mercury ions, the polyT:polyA duplex dehybridizes and a T–Hg 2+ –T duplex is formed. This structure switch leads to the release of polyA from the SWNT surface and correspondingly a change in the resistance of the chemiresistive biosensor is observed, which is used to quantify the mercury ion concentration. The biosensor showed a wide dynamic range of 0.5 to 100 nM for the detection of CH 3 Hg + ions in buffer solution with a sensitivity of 28.34% per log (nM) of CH 3 Hg +. Finally, real world application of the biosensor was demonstrated by the detection of Hg 2+ and CH 3 Hg + ions in simulated saliva samples spiked with a known concentration of mercury ions.
Carbon nanotubes and graphene nano field-effect transistor-based biosensors
TrAC Trends in Analytical Chemistry, 2015
Affinity chemiresistor sensor for sugars
Talanta, 2014
In this work, a non-enzymatic chemiresistive sugar sensor has been developed by combining a synth... more In this work, a non-enzymatic chemiresistive sugar sensor has been developed by combining a synthetic receptor with aligned single-walled carbon nanotubes (SWNTs) device. Briefly, boronic acid as a multivalent sugar receptor was immobilized on carbon nanotubes through amide bond formation. The interaction between three common sugars (d-glucose, d-fructose and sucrose) and boronic acid modified SWNTs device was studied. The effect of pH on the receptor-ligand binding was examined and highest response was observed at pH 9. The chemiresistive sensor exhibited specific and reproducible detection with sensitivity over the concentration range of 1-20mM, 1-25 mM, and 1-30 mM for fructose, glucose, and sucrose, respectively. The sensor showed no interference from common electroactive compounds such as citric acid, uric acid, and ascorbic acid. Furthermore, the sensor retained 97.4% of the initial value after five regeneration cycles with an acidic buffer at pH 5, thus ensuring good reusability.
Divalent mercuric (Hg 2+) ion and monomethyl mercury (CH 3 Hg +) are two forms of mercury that ar... more Divalent mercuric (Hg 2+) ion and monomethyl mercury (CH 3 Hg +) are two forms of mercury that are known to be highly toxic to humans. In this work, we present a highly selective, sensitive and label-free chemiresistive biosensor for the detection of both, Hg 2+ and CH 3 Hg + ions using DNA-functionalized single-walled carbon nanotubes (SWNTs). The SWNTs were functionalized with the capture oligo-nucleotide, polyT, using a linker molecule. The polyT was hybridized with polyA to form a polyT:polyA duplex. Upon exposure to mercury ions, the polyT:polyA duplex dehybridizes and a T–Hg 2+ –T duplex is formed. This structure switch leads to the release of polyA from the SWNT surface and correspondingly a change in the resistance of the chemiresistive biosensor is observed, which is used to quantify the mercury ion concentration. The biosensor showed a wide dynamic range of 0.5 to 100 nM for the detection of CH 3 Hg + ions in buffer solution with a sensitivity of 28.34% per log (nM) of CH 3 Hg +. Finally, real world application of the biosensor was demonstrated by the detection of Hg 2+ and CH 3 Hg + ions in simulated saliva samples spiked with a known concentration of mercury ions.