161 results on '"Vilaivan T"'
Search Results
2. P1BS.2 - Electrochemical Paper-based DNA Sensor for Human Papillomavirus Detection
- Author
-
Teengam, P., primary, Vilaivan, T., additional, Chailapakul, O., additional, Siangproh, W., additional, Tuantranont, A., additional, and Henry, C. S., additional
- Published
- 2018
- Full Text
- View/download PDF
3. Recyclable magnetite nanoparticle coated with cationic polymers for adsorption of DNA
- Author
-
Rutnakornpituk, B., primary, Theppaleak, T., additional, Rutnakornpituk, M., additional, and Vilaivan, T., additional
- Published
- 2016
- Full Text
- View/download PDF
4. Anion-exchanged nanosolid support of magnetic nanoparticle in combination with PNA probes for DNA sequence analysis
- Author
-
Theppaleak, T., Rutnakornpituk, M., Wichai, U., Vilaivan, T., and Rutnakornpituk, B.
- Published
- 2013
- Full Text
- View/download PDF
5. Magnetite Nanoparticle with Positively Charged Surface for Immobilization of Peptide Nucleic Acid and Deoxyribonucleic Acid
- Author
-
Theppaleak, T., primary, Rutnakornpituk, B., additional, Wichai, U., additional, Vilaivan, T., additional, and Rutnakornpituk, M., additional
- Published
- 2013
- Full Text
- View/download PDF
6. Human dihydrofolate reductase complexed with NADPH and P218
- Author
-
Yuthavong, Y., primary, Tarnchompoo, B., additional, Vilaivan, T., additional, Chitnumsub, P., additional, Kamchonwongpaisan, S., additional, Charman, S.A., additional, McLennan, D.N., additional, White, K.L., additional, Vivas, L., additional, Bongard, E., additional, Thongphanchang, C., additional, Taweechai, S., additional, Vanichtanankul, J., additional, Rattanajak, R., additional, Arwon, U., additional, Fantauzzi, P., additional, Yuvaniyama, J., additional, Charman, W.N., additional, and Matthews, D., additional
- Published
- 2012
- Full Text
- View/download PDF
7. Quadruple mutant (N51I+C59R+S108N+I164L) Plasmodium falciparum dihydrofolate reductase-thymidylate synthase (PfDHFR-TS) complexed with P65 and NADPH
- Author
-
Yuthavong, Y., primary, Vilaivan, T., additional, Kamchonwongpaisan, S., additional, Charman, S.A., additional, McLennan, D.N., additional, White, K.L., additional, Vivas, L., additional, Bongard, E., additional, Chitnumsub, P., additional, Tarnchompoo, B., additional, Thongphanchang, C., additional, Taweechai, S., additional, Vanichtanakul, J., additional, Arwon, U., additional, Fantauzzi, P., additional, Yuvaniyama, J., additional, Charman, W.N., additional, and Matthews, D., additional
- Published
- 2012
- Full Text
- View/download PDF
8. WILD TYPE PLASMODIUM FALCIPARUM DIHYDROFOLATE REDUCTASE-THYMIDYLATE SYNTHASE (PfDHFR-TS), DHF COMPLEX, NADP+, dUMP
- Author
-
Yuthavong, Y., primary, Vilaivan, T., additional, Kamchonwongpaisan, S., additional, Charman, S.A., additional, McLennan, D.N., additional, White, K.L., additional, Vivas, L., additional, Bongard, E., additional, Chitnumsub, P., additional, Tarnchompoo, B., additional, Thongphanchang, C., additional, Taweechai, S., additional, Vanichtanakul, J., additional, Arwon, U., additional, Fantauzzi, P., additional, Yuvaniyama, J., additional, Charman, W.N., additional, and Matthews, D., additional
- Published
- 2012
- Full Text
- View/download PDF
9. POSTHARVEST NON-DESTRUCTIVE DETERMINATION OF FRUITS: A MODEL ON FRUIT MATURITY ASSAY VIA BIOSENSOR BASED ON COLORIMETRIC CHANGE OF GOLD NANOPARTICLES
- Author
-
Chaumpluk, P., primary, Chaiprasart, P., additional, and Vilaivan, T., additional
- Published
- 2012
- Full Text
- View/download PDF
10. A nested sequence-specific primer-polymerase chain reaction for the detection of HLA-B*15:02
- Author
-
Virakul, S., primary, Kupatawintu, P., additional, Nakkuntod, J., additional, Kangwanshiratada, O., additional, Vilaivan, T., additional, and Hirankarn, N., additional
- Published
- 2012
- Full Text
- View/download PDF
11. Ion-Exchange Capture of Labeled Pyrrolidinyl Peptide Nucleic Acids for DNA Sequence Determination
- Author
-
Korkaew, P., primary and Vilaivan, T., additional
- Published
- 2008
- Full Text
- View/download PDF
12. Malarial (Plasmodium falciparum) dihydrofolate reductase-thymidylate synthase: structural basis for antifolate resistance and development of effective inhibitors
- Author
-
YUTHAVONG, Y., primary, YUVANIYAMA, J., additional, CHITNUMSUB, P., additional, VANICHTANANKUL, J., additional, CHUSACULTANACHAI, S., additional, TARNCHOMPOO, B., additional, VILAIVAN, T., additional, and KAMCHONWONGPAISAN, S., additional
- Published
- 2005
- Full Text
- View/download PDF
13. Labdane diterpenoids from Croton oblongifolius
- Author
-
Roengsumran, S, primary, Petsom, A, additional, Sommit, D, additional, and Vilaivan, T, additional
- Published
- 1999
- Full Text
- View/download PDF
14. ChemInform Abstract: Dipeptides Bearing Nucleobases for the Synthesis of Novel Peptide Nucleic Acids.
- Author
-
LOWE, G., primary and VILAIVAN, T., additional
- Published
- 1997
- Full Text
- View/download PDF
15. ChemInform Abstract: Amino Acids Bearing Nucleobases for the Synthesis of Novel Peptide Nucleic Acids.
- Author
-
LOWE, G., primary and VILAIVAN, T., additional
- Published
- 1997
- Full Text
- View/download PDF
16. Strand displacement and duplex invasion into double-stranded DNA by pyrrolidinyl peptide nucleic acids
- Author
-
Bohländer, P. R., Vilaivan, T., and Wagenknecht, H.-A.
- Subjects
Chemistry & allied sciences ,ddc:540 - Abstract
The so-called acpcPNA system bears a peptide backbone consisting of 4′-substituted proline units with (2′R,4′R) configuration in an alternating combination with (2S)-amino-cyclopentane-(1S)-carboxylic acids. acpcPNA forms exceptionally stable hybrids with complementary DNA. We demonstrate herein (i) strand displacements by single-stranded DNA from acpcPNA-DNA hybrids, and by acpcPNA strands from DNA duplexes, and (ii) strand invasions by acpcPNA into double-stranded DNA. These processes were studied in vitro using synthetic oligonucleotides and by means of our concept of wavelength-shifting fluorescent nucleic acid probes, including fluorescence lifetime measurements that allow quantifying energy transfer efficiencies. The strand displacements of preannealed 14mer acpcPNA-7mer DNA hybrids consecutively by 10mer and 14mer DNA strands occur with rather slow kinetics but yield high fluorescence color ratios (blue:yellow or blue:red), fluorescence intensity enhancements, and energy transfer efficiencies. Furthermore, 14mer acpcPNA strands are able to invade into 30mer double-stranded DNA, remarkably with quantitative efficiency in all studied cases. These processes can also be quantified by means of fluorescence. This remarkable behavior corroborates the extraordinary versatile properties of acpcPNA. In contrast to conventional PNA systems which require 3 or more equivalents PNA, only 1.5 equivalents acpcPNA are sufficient to get efficient double duplex invasion. Invasions also take place even in the presence of 250 mM NaCl which represents an ionic strength nearly twice as high as the physiological ion concentration. These remarkable results corroborate the extraordinary properties of acpcPNA, and thus acpcPNA represents an eligible tool for biological analytics and antigene applications. © The Royal Society of Chemistry 2015.
- Published
- 2015
- Full Text
- View/download PDF
17. Inhibitors of Multiple Mutants of Plasmodium falciparum Dihydrofolate Reductase and Their Antimalarial Activities
- Author
-
Kamchonwongpaisan, S., Quarrell, R., Charoensetakul, N., Ponsinet, R., Vilaivan, T., Vanichtanankul, J., Tarnchompoo, B., Sirawaraporn, W., Lowe, G., and Yuthavong, Y.
- Abstract
Novel analogues of pyrimethamine (Pyr) and cycloguanil (Cyc) have been synthesized and tested as inhibitors of Plasmodium falciparum dihydrofolate reductase carrying triple (N51I+C59R+S108N, C59R+S108N+I164L) and quadruple (N51I+C59R+S108N+I164L) mutations responsible for antifolate resistance. The inhibitors were designed to avoid steric clash of the p-Cl group of the inhibitors with the side chain of Asn108, augmented by additional mutations of the resistant mutants. Cycloguanil derivatives were also designed to avoid steric clash with the side chain of Val16 in the A16V+S108T mutant. Many compounds have inhibition constants (K
i ) at the low nanomolar level against the mutant enzymes and a number have good antimalarial activities against resistant P. falciparum parasites bearing multiple mutations in the S108N series and A16V+S108T mutant enzymes. These compounds in the Pyr and Cyc series exhibit low and moderate cytotoxicity to nontumor (Vero) and tumor (KB, BC) cell lines. Some of these inhibitors are therefore potential candidates for further development as antimalarials.- Published
- 2004
18. Development of a Lead Inhibitor for the A16V+S108T Mutant of Dihydrofolate Reductase from the Cycloguanil-Resistant Strain (T9/94) of Plasmodium falciparum<SUP></SUP>
- Author
-
Yuthavong, Y., Vilaivan, T., Chareonsethakul, N., Kamchonwongpaisan, S., Sirawaraporn, W., Quarrell, R., and Lowe, G.
- Abstract
The Ala16Val+Ser108Thr (A16V+S108T) mutant of the Plasmodium falciparum dihydrofolate reductase (DHFR) is a key mutant responsible for cycloguanil-resistant malaria due to steric interaction between Val-16 and one of the C-2 methyl groups of cycloguanil. 4,6-Diamino-1,2-dihydrotriazines have been prepared, in which both methyl groups of cycloguanil are replaced by H or by H and an alkyl or phenyl group, and their inhibition constants against wild-type and mutant DHFR determined. The S108T mutation is considered to decrease cycloguanil binding further through the effect on the orientation of the p-chlorophenyl group. By moving the p-chloro-substituent to the m-position in the chlorophenyl group, the activity against the A16V+S108T mutant enzyme is improved, and this effect is reinforced by the p-chloro substituent in the 3,4-dichlorophenyl group. A lead compound has been found with inhibitory activity similar to that of cycloguanil against the wild-type DHFR and about 120-fold more effective than cycloguanil against the A16V+S108T mutant enzyme. The activity of this compound against P. falciparum clone (T9/94 RC17) which harbors the A16V+S108T DHFR is about 85-fold greater than cycloguanil.
- Published
- 2000
19. Synthesis and properties of chiral peptide nucleic acids with a N-Aminoethyl-d-proline backbone
- Author
-
Vilaivan, T., Khongdeesameor, C., Harnyuttanakorn, P., Westwell, M. S., and Lowe, G.
- Published
- 2000
- Full Text
- View/download PDF
20. Cytotoxicity of (2,2:6,2 -Terpyridine)platinum(II) Complexes to Leishmania donovani, Trypanosoma cruzi, and Trypanosoma brucei
- Author
-
Lowe, G., Droz, A. S., Vilaivan, T., Weaver, G. W., Tweedale, L., Pratt, J. M., Rock, P., Yardley, V., and Croft, S. L.
- Abstract
A range of (2,2:6,2 -terpyridine)platinum(II) complexes are shown to possess antiprotozoal activity in vitro against Leishmania donovani, Trypanosoma cruzi, and Trypanosoma brucei, the causative organisms of tropical diseases leishmaniasis and trypanosomiasis. The best compounds caused 100% and 78% inhibition of growth of the intracellular amastigote forms of L. donovani and T. cruzi, respectively, at a concentration of 1 μM and 100% inhibition of growth of the bloodstream trypomastigote forms of T. brucei at a concentration of 0.03 μM. The results obtained with complexes in which the fourth ligand to platinum(II) is capable of being substituted with a substitution inert hydroxyethanethiolate complex are compared. The ammine complexes show high antiprotozoal activity suggesting that the trans influence of the 2,2:6,2 -terpyridine ligand has a profound effect on the ease of displacement of the fourth ligand in (2,2:6,2 -terpyridine)platinum(II) complexes, although nonbonded interaction between the ammine ligand and the 6 and 6 hydrogens probably also weakens the ligation to Pt(II).
- Published
- 1999
21. Cytotoxicity of 2,2:6,2 -Terpyridineplatinum(II) Complexes against Human Ovarian Carcinoma
- Author
-
Lowe, G., Droz, A. S., Vilaivan, T., Weaver, G. W., Park, J. J., Pratt, J. M., Tweedale, L., and Kelland, L. R.
- Abstract
2,2:6,2 -Terpyridineplatinum(II) complexes are shown to possess cytotoxicity against a number of human ovarian tumor cell lines. Many of the complexes show similar activity against cisplatin- and doxorubicin-resistant cell lines as the parental cells suggesting that there is little or no cross-resistance with cisplatin or doxorubicin. The cytotoxicity of bis[2,2:6,2 -terpyridineplatinum(II)] complexes is strongly dependent on the nature of the linker. Bis[2,2:6,2 -terpyridineplatinum(II)] complexes with a flexible linker at the 4-position show poor cytotoxicity; by contrast bis[2,2:6,2 -terpyridineplatinum(II)] complexes with rigid and short linkers at platinum(II) are strikingly effective. Several of the compounds show greater cytotoxicity against human ovarian cell lines than carboplatin, the therapeutic agent currently advocated for the treatment of human ovarian cancers.
- Published
- 1999
22. Labdane diterpenoids from Croton oblongifolius
- Author
-
Roengsumran, S., Petsom, A., Sommit, D., and Vilaivan, T.
- Published
- 1998
- Full Text
- View/download PDF
23. Synthesis of 2-[4-(Ethylcarbamoyl)phenyl]-N-acetylglycine, the Proposed Structure for Giganticine
- Author
-
Suparpprom, C. and Vilaivan, T.
- Abstract
A compound (
1 ) with the structure proposed for giganticine, an antifeedant principle isolated from the root bark of Caloropis gigantea, has been successfully synthesized by two independent methods. Comparison of physical properties and spectroscopic data of1 with giganticine revealed that they are different compounds. All available evidence suggests that the proposed structure of giganticine is incorrect.- Published
- 2001
24. Two New Cembranoids from Croton oblongifolius
- Author
-
Roengsumran, S., Achayindee, S., Petsom, A., Pudhom, K., Singtothong, P., Surachetapan, C., and Vilaivan, T.
- Abstract
Two new cembranoids, crotocembraneic acid (
1 ) and neocrotocembraneic acid (2 ), were isolated from the stem bark of Croton oblongifolius. Their structures were established on the basis of spectroscopic analysis.- Published
- 1998
25. Plasmodium serine hydroxymethyltransferase as a potential anti-malarial target: inhibition studies using improved methods for enzyme production and assay
- Author
-
Sopitthummakhun Kittipat, Thongpanchang Chawanee, Vilaivan Tirayut, Yuthavong Yongyuth, Chaiyen Pimchai, and Leartsakulpanich Ubolsree
- Subjects
Serine hydroxymethyltransferase ,Plasmodium falciparum ,Plasmodium vivax ,Pyridoxal-5-phosphate dependent enzyme ,Thiosemicarbazide ,Arctic medicine. Tropical medicine ,RC955-962 ,Infectious and parasitic diseases ,RC109-216 - Abstract
Abstract Background There is an urgent need for the discovery of new anti-malarial drugs. Thus, it is essential to explore different potential new targets that are unique to the parasite or that are required for its viability in order to develop new interventions for treating the disease. Plasmodium serine hydroxymethyltransferase (SHMT), an enzyme in the dTMP synthesis cycle, is a potential target for such new drugs, but convenient methods for producing and assaying the enzyme are still lacking, hampering the ability to screen inhibitors. Methods Production of recombinant Plasmodium falciparum SHMT (PfSHMT) and Plasmodium vivax SHMT (PvSHMT), using auto-induction media, were compared to those using the conventional Luria Bertani medium with isopropyl thio-β-D-galactoside (LB-IPTG) induction media. Plasmodium SHMT activity, kinetic parameters, and response to inhibitors were measured spectrophotometrically by coupling the reaction to that of 5,10-methylenetetrahydrofolate dehydrogenase (MTHFD). The identity of the intermediate formed upon inactivation of Plasmodium SHMTs by thiosemicarbazide was investigated by spectrophotometry, high performance liquid chromatography (HPLC), and liquid chromatography-mass spectrometry (LC-MS). The active site environment of Plasmodium SHMT was probed based on changes in the fluorescence emission spectrum upon addition of amino acids and folate. Results Auto-induction media resulted in a two to three-fold higher yield of Pf- and PvSHMT (7.38 and 29.29 mg/L) compared to that produced in cells induced in LB-IPTG media. A convenient spectrophotometric activity assay coupling Plasmodium SHMT and MTHFD gave similar kinetic parameters to those previously obtained from the anaerobic assay coupling SHMT and 5,10-methylenetetrahydrofolate reductase (MTHFR); thus demonstrating the validity of the new assay procedure. The improved method was adopted to screen for Plasmodium SHMT inhibitors, of which some were originally designed as inhibitors of malarial dihydrofolate reductase. Plasmodium SHMT was slowly inactivated by thiosemicarbazide and formed a covalent intermediate, PLP-thiosemicarbazone. Conclusions Auto-induction media offers a cost-effective method for the production of Plasmodium SHMTs and should be applicable for other Plasmodium enzymes. The SHMT-MTHFD coupled assay is equivalent to the SHMT-MTHFR coupled assay, but is more convenient for inhibitor screening and other studies of the enzyme. In addition to inhibitors of malarial SHMT, the development of species-specific, anti-SHMT inhibitors is plausible due to the presence of differential active sites on the Plasmodium enzymes.
- Published
- 2012
- Full Text
- View/download PDF
26. Indium mediated Barbier-type allylation of aldimines in alcoholic solvents
- Author
-
Vilaivan, T
- Published
- 2001
27. Synthesis and properties of novel pyrrolidinyl PNA carrying β-amino acid spacers
- Author
-
Vilaivan, T
- Published
- 2001
28. Nucleic Acid-Templated Synthesis of Cationic Styryl Dyes in Vitro and in Living Cells.
- Author
-
Faikhruea K, Supabowornsathit K, Angsujinda K, Aonbangkhen C, Chaikeeratisak V, Palaga T, Assavalapsakul W, Wagenknecht HA, and Vilaivan T
- Abstract
A novel method for synthesizing cationic styryl dyes through a nucleic acid-templated reaction has been developed. This approach overcomes issues associated with traditional synthesis methods, such as harsh conditions, low throughput, and wasteful chemicals. The presence of a nucleic acid template accelerated the styryl dye formation from quaternized heteroaromatic and cationic aldehyde substrates. These styryl dyes show remarkable optical properties change when bound to nucleic acids, hence the success of the synthesis could be readily monitored in situ by UV-Vis and fluorescence spectroscopy and the optical properties data were also observable at the same time. This method provides the desired products from a broad range of coupling partners. By employing different substrates and templates, it is possible to identify new dyes that can bind to a specific type of nucleic acid such as a G-quadruplex. The templated dye synthesis is also successfully demonstrated in live HeLa cells. This approach is a powerful tool for the rapid synthesis and screening of dyes specific for diverse types of nucleic acids or cellular organelles, facilitating new biological discoveries., (© 2024 Wiley-VCH GmbH.)
- Published
- 2024
- Full Text
- View/download PDF
29. Design, Synthesis, and Characterization of Novel Styryl Dyes as Fluorescent Probes for Tau Aggregate Detection in Vitro and in Cells.
- Author
-
Sangsuwan W, Faikhruea K, Supabowornsathit K, Sangsopon D, Ingrungruanglert P, Chuntakaruk H, Nuntavanotayan N, Nakprasit K, Israsena N, Rungrotmongkol T, Chuawong P, Vilaivan T, and Aonbangkhen C
- Subjects
- Molecular Docking Simulation, Microscopy, Fluorescence, Fluorescent Dyes chemistry
- Abstract
A series of novel styryl dye derivatives incorporating indolium and quinolinium core structures were successfully synthesized to explore their interacting and binding capabilities with tau aggregates in vitro and in cells. The synthesized dyes exhibited enhanced fluorescence emission in viscous environments due to the rotatable bond confinement in the core structure. Dye 4, containing a quinolinium moeity and featuring two cationic sites, demonstrated a 28-fold increase in fluorescence emission upon binding to tau aggregates. This dye could also stain tau aggregates in living cells, confirmed by cell imaging using confocal fluorescence microscopy. A molecular docking study was conducted to provide additional visualization and support for binding interactions. This work offers novel and non-cytotoxic fluorescent probes with desirable photophysical properties, which could potentially be used for studying tau aggregates in living cells, prompting further development of new fluorescent probes for early Alzheimer's disease detection., (© 2024 Wiley‐VCH GmbH.)
- Published
- 2024
- Full Text
- View/download PDF
30. Cricket Protein Isolate Extraction: Effect of Ammonium Sulfate on Physicochemical and Functional Properties of Proteins.
- Author
-
Edward, Wongprasert T, Bunyakanchana T, Siripitakpong P, Supabowornsathit K, Vilaivan T, and Suppavorasatit I
- Abstract
Crickets are known to be a promising alternative protein source. However, a negative consumer bias and an off-flavor have become obstacles to the use of these insects in the food industry. In this study, we extracted the protein from commercial cricket powder by employing alkaline extraction-acid precipitation and including ammonium sulfate. The physicochemical and functional properties of the proteins were determined. It was found that, upon including 60% ammonium sulfate, the cricket protein isolate (CPI) had the highest protein content (~94%, w / w ). The circular dichroism results indicated that a higher amount of ammonium sulfate drastically changed the secondary structure of the CPI by decreasing its α-helix content and enhancing its surface hydrophobicity. The lowest solubility of CPI was observed at pH 5. The CPI also showed better foaming properties and oil-holding capacity (OHC) compared with the cricket powder. In conclusion, adding ammonium sulfate affected the physicochemical and functional properties of the CPI, allowing it to be used as an alternative protein in protein-enriched foods and beverages.
- Published
- 2023
- Full Text
- View/download PDF
31. Focusing ion funnel-assisted ambient electrospray enables high-density and uniform deposition of non-spherical gold nanoparticles for highly sensitive surface-enhanced Raman scattering.
- Author
-
Akbali B, Boisdon C, Smith BL, Chaisrikhwun B, Wongravee K, Vilaivan T, Lima C, Huang CH, Chen TY, Goodacre R, and Maher S
- Abstract
Surface-enhanced Raman scattering (SERS) is a powerful technique for detecting trace amounts of analytes. However, the performance of SERS substrates depends on many variables including the enhancement factor, morphology, consistency, and interaction with target analytes. In this study, we investigated, for the first time, the use of electrospray deposition (ESD) combined with a novel ambient focusing DC ion funnel to deposit a high density of gold nanoparticles (AuNPs) to generate large-area, uniform substrates for highly sensitive SERS analysis. We found that the combination of ambient ion focusing with ESD facilitated high-density and intact deposition of non-spherical NPs. This also allowed us to take advantage of a polydisperse colloidal solution of AuNPs (consisting of nanospheres and nanorods), as confirmed by finite-difference time domain (FDTD) simulations. Our SERS substrate exhibited excellent capture capacity for model analyte molecules, namely 4-aminothiophenol (4-ATP) and Rhodamine 6G (R6G), with detection limits in the region of 10
-11 M and a relative standard deviation of <6% over a large area (∼500 × 500 μm2 ). Additionally, we assessed the quantitative performance of our SERS substrate using the R6G probe molecule. The results demonstrated excellent linearity ( R2 > 0.99) over a wide concentration range (10-4 M to 10-10 M) with a detection limit of 80 pM.- Published
- 2023
- Full Text
- View/download PDF
32. Sequential Flow Controllable Microfluidic Device for G-Quadruplex DNAzyme-Based Electrochemical Detection of SARS-CoV-2 Using a Pyrrolidinyl Peptide Nucleic Acid.
- Author
-
Naorungroj S, Srisomwat C, Khamcharoen W, Jampasa S, Pasomsub E, Shin K, Vilaivan T, and Chailapakul O
- Subjects
- Humans, SARS-CoV-2, COVID-19 Testing, Hydrogen Peroxide, DNA, Catalytic, COVID-19 diagnosis, Peptide Nucleic Acids
- Abstract
The coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been a significant health issue globally. Point-of-care (POC) testing that can offer a rapid and accurate diagnosis of SARS-CoV-2 at the early stage of infection is highly desirable to constrain this outbreak, especially in resource-limited settings. Herein, we present a G-quadruplex DNAzyme-based electrochemical assay that is integrated with a sequential flow controllable microfluidic device for the detection of SARS-CoV-2 cDNA. According to the detection principle, a pyrrolidinyl peptide nucleic acid probe is immobilized on a screen-printed graphene electrode for capturing SARS-CoV-2 DNA. The captured DNA subsequently hybridizes with another DNA probe that carries a G-quadruplex DNAzyme as the signaling unit. The G-quadruplex DNAzyme catalyzes the H
2 O2 -mediated oxidation of hydroquinone to benzoquinone that can be detected using square-wave voltammetry to give a signal that corresponds to the target DNA concentration. The assay exhibited high selectivity for SARS-CoV-2 DNA and showed a good experimental detection limit at 30 pM. To enable automation, the DNAzyme-based assay was combined with a capillary-driven microfluidic device featuring a burst valve technology to allow sequential sample and reagent delivery as well as the DNA target hybridization and enzymatic reaction to be operated in a precisely controlled fashion. The developed microfluidic device was successfully applied for the detection of SARS-CoV-2 from nasopharyngeal swab samples. The results were in good agreement with the standard RT-PCR method and could be performed within 20 min. Thus, this platform offers desirable characteristics that make it an alternative POC tool for COVID-19 diagnosis.- Published
- 2023
- Full Text
- View/download PDF
33. Development of peptide nucleic acid-based bead array technology for Bacillus cereus detection.
- Author
-
Noppakuadrittidej P, Charlermroj R, Makornwattana M, Kaew-Amdee S, Waditee-Sirisattha R, Vilaivan T, Praneenararat T, and Karoonuthaisiri N
- Subjects
- RNA, Ribosomal, 16S genetics, Polymerase Chain Reaction methods, DNA, Food Microbiology, Bacillus cereus genetics, Peptide Nucleic Acids
- Abstract
Numerous novel methods to detect foodborne pathogens have been extensively developed to ensure food safety. Among the important foodborne bacteria, Bacillus cereus was identified as a pathogen of concern that causes various food illnesses, leading to interest in developing effective detection methods for this pathogen. Although a standard method based on culturing and biochemical confirmative test is available, it is time- and labor-intensive. Alternative PCR-based methods have been developed but lack high-throughput capacity and ease of use. This study, therefore, attempts to develop a robust method for B. cereus detection by leveraging the highly specific pyrrolidinyl peptide nucleic acids (PNAs) as probes for a bead array method with multiplex and high-throughput capacity. In this study, PNAs bearing prolyl-2-aminocyclopentanecarboxylic acid (ACPC) backbone with groEL, motB, and 16S rRNA sequences were covalently coupled with three sets of fluorescently barcoded beads to detect the three B. cereus genes. The developed acpcPNA-based bead array exhibited good selectivity where only signals were detectable in the presence of B. cereus, but not for other species. The sensitivity of this acpcPNA-based bead assay in detecting genomic DNA was found to be 0.038, 0.183 and 0.179 ng for groEL, motB and 16S rRNA, respectively. This performance was clearly superior to its DNA counterpart, hence confirming much stronger binding strength of acpcPNA over DNA. The robustness of the developed method was further demonstrated by testing artificially spiked milk and pickled mustard greens with minimal interference from food metrices. Hence, this proof-of-concept acpcPNA-based bead array method has been proven to serve as an effective alternative nucleic acid-based method for foodborne pathogens., (© 2023. The Author(s).)
- Published
- 2023
- Full Text
- View/download PDF
34. Electrochemical capillary-driven microfluidic DNA sensor for HIV-1 and HCV coinfection analysis.
- Author
-
Chittuam K, Jampasa S, Vilaivan T, Tangkijvanich P, Chuaypen N, Avihingsanon A, Sain M, Panraksa Y, and Chailapakul O
- Subjects
- Humans, Hepacivirus genetics, Microfluidics, DNA, Complementary, DNA, HIV-1 genetics, Coinfection, Hepatitis C diagnosis, HIV Infections diagnosis
- Abstract
Electrochemical DNA sensors can be operated in either static or flow-based detection schemes. In static schemes, manual washing steps are still necessary, resulting in a tedious and time-consuming process. In contrast, in flow-based electrochemical sensors, the current response is collected when the solution flows through the electrode continuously. However, the drawback of such a flow system is the low sensitivity due to the limited time for the interaction between the capturing element and the target. Herein, we propose a novel electrochemical capillary-driven microfluidic DNA sensor to combine the advantages of static and flow-based electrochemical detection systems into a single device by incorporating burst valve technology. The microfluidic device with a two-electrode configuration was applied for the simultaneous detection of two different DNA markers, human immunodeficiency virus-1 (HIV-1) and hepatitis C virus (HCV) cDNA, via the specific interaction between pyrrolidinyl peptide nucleic acids (PNA) probes and the DNA target. The integrated system, while requiring a small sample volume (7 μL for each sample loading port) and less analysis time, achieved good performance in terms of the limits of detection (LOD) (3SD
blank /slope) and quantification (LOQ) (10SDblank /slope) at 1.45 nM and 4.79 nM for HIV and 1.20 nM and 3.96 nM for HCV, respectively. The simultaneous detection of HIV-1 and HCV cDNA prepared from human blood samples showed results that are in complete agreement with the RT‒PCR assay. The results qualify this platform as a promising alternative for the analysis of either HIV-1/HCV or coinfection that can be easily adapted for other clinically important nucleic acid-based markers., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)- Published
- 2023
- Full Text
- View/download PDF
35. Cyanostilbene-based fluorescent paper array for monitoring fish and meat freshness via amino content detection.
- Author
-
Dhinakaran MK, Smith BL, Vilaivan T, Maher S, and Praneenararat T
- Subjects
- Animals, Cattle, Coloring Agents, Fishes, Chickens, Meat analysis, Biogenic Amines analysis
- Abstract
The detection of biogenic amines released from degraded meats is an effective method for evaluating meat freshness. However, existing traditional methods like titration are deemed tedious, while the use of sophisticated analytical instruments is not amenable to field testing. Herein, a cyanostilbene-based fluorescent array was rapidly fabricated using macroarray synthesis on a cellulose paper surface to detect amines liberated from spoiled beef, fish, and chicken. The fluorescence changes of immobilized molecules from the interaction with gaseous amines were used to monitor changes in freshness levels. Thanks to the high-throughput nature of macroarray synthesis, a set of highly responsive molecules such as pyridinium and dicyanovinyl moieties were quickly revealed. Importantly, this method offers flexibility in sensing applications including (1) sensing by individual sensor molecules, where the fluorescence response correlated well with established titration methods, and (2) collective sensing whereby chemometric analysis was used to provide a cutoff of freshness with 73-100% accuracy depending on meat types. Overall, this study paves the way for a robust and cost-effective tool for monitoring meat freshness., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Austria, part of Springer Nature.)
- Published
- 2023
- Full Text
- View/download PDF
36. Label free electrochemical DNA biosensor for COVID-19 diagnosis.
- Author
-
Lomae A, Preechakasedkit P, Hanpanich O, Ozer T, Henry CS, Maruyama A, Pasomsub E, Phuphuakrat A, Rengpipat S, Vilaivan T, Chailapakul O, Ruecha N, and Ngamrojanavanich N
- Subjects
- Humans, SARS-CoV-2 genetics, COVID-19 Testing, Pandemics, DNA, COVID-19 diagnosis
- Abstract
The COVID-19 pandemic has significantly increased the development of the development of point-of-care (POC) diagnostic tools because they can serve as useful tools for detecting and controlling spread of the disease. Most current methods require sophisticated laboratory instruments and specialists to provide reliable, cost-effective, specific, and sensitive POC testing for COVID-19 diagnosis. Here, a smartphone-assisted Sensit Smart potentiostat (PalmSens) was integrated with a paper-based electrochemical sensor to detect severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). A disposable paper-based device was fabricated, and the working electrode directly modified with a pyrrolidinyl peptide nucleic acid (acpcPNA) as the biological recognition element to capture the target complementary DNA (cDNA). In the presence of the target cDNA, hybridization with acpcPNA probe blocks the redox conversion of a redox reporter, leading to a decrease in electrochemical response correlating to SARS-CoV-2 concentration. Under optimal conditions, a linear range from 0.1 to 200 nM and a detection limit of 1.0 pM were obtained. The PNA-based electrochemical paper-based analytical device (PNA-based ePAD) offers high specificity toward SARS-CoV-2 N gene because of the highly selective PNA-DNA binding. The developed sensor was used for amplification-free SARS-CoV-2 detection in 10 nasopharyngeal swab samples (7 SARS-CoV-2 positive and 3 SARS-CoV-2 negative), giving a 100% agreement result with RT-PCR., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)
- Published
- 2023
- Full Text
- View/download PDF
37. Dicationic styryl dyes for colorimetric and fluorescent detection of nucleic acids.
- Author
-
Supabowornsathit K, Faikhruea K, Ditmangklo B, Jaroenchuensiri T, Wongsuwan S, Junpra-Ob S, Choopara I, Palaga T, Aonbangkhen C, Somboonna N, Taechalertpaisarn J, and Vilaivan T
- Subjects
- Colorimetry, DNA chemistry, Fluorescent Dyes chemistry, Spectrometry, Fluorescence, Nucleic Acids chemistry
- Abstract
Nucleic acid staining dyes are important tools for the analysis and visualizing of DNA/RNA in vitro and in the cells. Nevertheless, the range of commercially accessible dyes is still rather limited, and they are often very costly. As a result, finding nontoxic, easily accessible dyes, with desirable optical characteristics remains important. Styryl dyes have recently gained popularity as potential biological staining agents with many appealing properties, including a straightforward synthesis procedure, excellent photostability, tunable fluorescence, and high fluorescence quantum yield in the presence of nucleic acid targets with low background fluorescence signals. In addition to fluorescence, styryl dyes are strongly colored and exhibit solvatochromic properties which make them useful as colorimetric stains for low-cost and rapid testing of nucleic acids. In this work, novel dicationic styryl dyes bearing quaternary ammonium groups are designed to improve binding strength and optical response with target nucleic acids which contain a negatively charged phosphate backbone. Optical properties of the newly synthesized styryl dyes have been studied in the presence and absence of nucleic acid targets with the aim to find new dyes that can sensitively and specifically change fluorescence and/or color in the presence of nucleic acid targets. The binding interaction and optical response of the dicationic styryl dyes with nucleic acid were superior to the corresponding monocationic styryl dyes. Applications of the developed dyes for colorimetric detection of DNA in vitro and imaging of cellular nucleic acids are also demonstrated., (© 2022. The Author(s).)
- Published
- 2022
- Full Text
- View/download PDF
38. Assay Development and Identification of the First Plasmodium falciparum 7,8-dihydro-6-hydroxymethylpterin-pyrophosphokinase Inhibitors.
- Author
-
Hoarau M, Suwanakitti N, Varatthan T, Thiabma R, Rattanajak R, Charoensetakul N, Redman EK, Khotavivattana T, Vilaivan T, Yuthavong Y, and Kamchonwongpaisan S
- Subjects
- Humans, Malaria, Falciparum drug therapy, Malaria, Falciparum parasitology, Molecular Docking Simulation, Antimalarials chemistry, Diphosphotransferases antagonists & inhibitors, Plasmodium falciparum drug effects
- Abstract
In the fight towards eradication of malaria, identifying compounds active against new drug targets constitutes a key approach. Plasmodium falciparum 7,8-dihydro-6-hydroxymethylpterin-pyrophosphokinase ( Pf HPPK) has been advanced as a promising target, as being part of the parasite essential folate biosynthesis pathway while having no orthologue in the human genome. However, no drug discovery efforts have been reported on this enzyme. In this study, we conducted a three-step screening of our in-house antifolate library against Pf HPPK using a newly designed Pf HPPK-GFP protein construct. Combining virtual screening, differential scanning fluorimetry and enzymatic assay, we identified 14 compounds active against Pf HPPK. Compounds' binding modes were investigated by molecular docking, suggesting competitive binding with the HMDP substrate. Cytotoxicity and in vitro ADME properties of hit compounds were also assessed, showing good metabolic stability and low toxicity. The most active compounds displayed low micromolar IC
50 against drug-resistant parasites. The reported hit compounds constitute a good starting point for inhibitor development against Pf HPPK, as an alternative approach to tackle the malaria parasite.- Published
- 2022
- Full Text
- View/download PDF
39. Surfactant-Assisted Ozonolysis of Alkenes in Water: Mitigation of Frothing Using Coolade as a Low-Foaming Surfactant.
- Author
-
Buntasana S, Hayashi J, Saetung P, Klumphu P, Vilaivan T, and Padungros P
- Subjects
- Aerosols, Hydrogen Peroxide, Reducing Agents, Solvents, Surface-Active Agents, Water, Alkenes, Ozone
- Abstract
Aqueous-phase ozonolysis in the atmosphere is an important process during cloud and fog formation. Water in the atmosphere acts as both a reaction medium and a reductant during the ozonolysis. Inspired by the atmospheric aqueous-phase ozonolysis, we herein report the ozonolysis of alkenes in water assisted by surfactants. Several types of surfactants, including anionic, cationic, and nonionic surfactants, were investigated. Although most surfactants enhanced the solubility of alkenes in water, they also generated excessive foaming during the ozone bubbling, which led to the loss of products. Mitigation of the frothing was accomplished by using Coolade as a nonionic and low-foaming surfactant. Coolade-assisted ozonolysis of alkenes in water provided the desired carbonyl products in good yields and comparable to those achieved in organic solvents. During the ozonolysis reaction, water molecules trapped within the polyethylene glycol region of Coolade were proposed to intercept the Criegee intermediate to provide a hydroxy hydroperoxide intermediate. Decomposition of the hydroxy hydroperoxide led to formation of the carbonyl product without the need for a reductant typically required for the conventional ozonolysis using organic solvents. This study presents Coolade as an effective surfactant to improve the solubility of alkenes while mitigating frothing during the ozonolysis in water.
- Published
- 2022
- Full Text
- View/download PDF
40. Perspectives on conformationally constrained peptide nucleic acid (PNA): insights into the structural design, properties and applications.
- Author
-
Suparpprom C and Vilaivan T
- Abstract
Peptide nucleic acid or PNA is a synthetic DNA mimic that contains a sequence of nucleobases attached to a peptide-like backbone derived from N -2-aminoethylglycine. The semi-rigid PNA backbone acts as a scaffold that arranges the nucleobases in a proper orientation and spacing so that they can pair with their complementary bases on another DNA, RNA, or even PNA strand perfectly well through the standard Watson-Crick base-pairing. The electrostatically neutral backbone of PNA contributes to its many unique properties that make PNA an outstanding member of the xeno-nucleic acid family. Not only PNA can recognize its complementary nucleic acid strand with high affinity, but it does so with excellent specificity that surpasses the specificity of natural nucleic acids and their analogs. Nevertheless, there is still room for further improvements of the original PNA in terms of stability and specificity of base-pairing, direction of binding, and selectivity for different types of nucleic acids, among others. This review focuses on attempts towards the rational design of new generation PNAs with superior performance by introducing conformational constraints such as a ring or a chiral substituent in the PNA backbone. A large collection of conformationally rigid PNAs developed during the past three decades are analyzed and compared in terms of molecular design and properties in relation to structural data if available. Applications of selected modified PNA in various areas such as targeting of structured nucleic acid targets, supramolecular scaffold, biosensing and bioimaging, and gene regulation will be highlighted to demonstrate how the conformation constraint can improve the performance of the PNA. Challenges and future of the research in the area of constrained PNA will also be discussed., Competing Interests: There are no conflicts of interest to declare., (This journal is © The Royal Society of Chemistry.)
- Published
- 2022
- Full Text
- View/download PDF
41. Enhancing Peptide Nucleic Acid-Nanomaterial Interaction and Performance Improvement of Peptide Nucleic Acid-Based Nucleic Acid Detection by Using Electrostatic Effects.
- Author
-
Faikhruea K, Choopara I, Somboonna N, Assavalapsakul W, Kim BH, and Vilaivan T
- Subjects
- DNA chemistry, DNA Probes, Gold chemistry, Nucleic Acid Probes, RNA, Silver chemistry, Static Electricity, Metal Nanoparticles chemistry, Nucleic Acids, Peptide Nucleic Acids chemistry
- Abstract
Single-stranded peptide nucleic acid (PNA) probes interact strongly with several nanomaterials, and the interaction was diminished in the presence of complementary nucleic acid targets which forms the basis of many nucleic acid sensing platforms. As opposed to the negatively charged DNA probes, the charges on the PNA probes may be fine-tuned by incorporating amino acids with charged side chains. The contribution of electrostatic effects to the interaction between PNA probes and nanomaterials has been largely overlooked. This work reveals that electrostatic effects substantially enhanced the quenching of dye-labeled conformationally constrained pyrrolidinyl PNA probes by several nanomaterials including graphene oxide (GO), reduced graphene oxide, gold nanoparticles (AuNPs), and silver nanoparticles. The fluorescence quenching and the color change from red to purple in the case of AuNPs because of aggregation were inhibited in the presence of complementary nucleic acid targets. Thus, fluorescence and colorimetric assays for DNA and RNA that can distinguish even single-base-mismatched nucleic acids with improved sensitivity over conventional DNA probes were established. Both the GO- and AuNP-based sensing platforms have been successfully applied for the detection of real DNA and RNA samples in vitro and in living cells. This study emphasizes the active roles of electrostatic effects in the PNA-nanomaterial interactions, which paves the way toward improving the performance of PNA-nanomaterial based assays of nucleic acids.
- Published
- 2022
- Full Text
- View/download PDF
42. An alternative label-free DNA sensor based on the alternating-current electroluminescent device for simultaneous detection of human immunodeficiency virus and hepatitis C co-infection.
- Author
-
Srisomwat C, Yakoh A, Avihingsanon A, Chuaypen N, Tangkijvanich P, Vilaivan T, and Chailapakul O
- Subjects
- DNA, Viral genetics, HIV genetics, Hepacivirus genetics, Humans, Biosensing Techniques, Coinfection, HIV Infections complications, HIV Infections diagnosis, Hepatitis C diagnosis
- Abstract
Coinfection of HIV/HCV is a significant public health issue globally, as it increases the risk of liver cancer in co-infected individuals. The point-of-care testing (POCT) device for HIV/HCV DNA detection is promptly needed for diagnosis and monitoring of the disease progression. Here, the alternating-current electroluminescence (ACEL) technique is proposed as a sensitive POCT sensing platform for HIV/HCV cDNA detection. A conductance-based light emission modulated by the hybridization between a pyrrolidinyl PNA probe and the DNA target enabled the DNA detection in a label-free format. Enhanced electroluminescence was observed in the presence of the target DNA due to the increased proton conductivity. Under the optimal conditions, the linearity range from 1 nM to 1 μM was achieved for HIV and HCV cDNA with LODs of 1.86 pM (HIV cDNA) and 1.96 pM (HCV cDNA). The spiked HIV/HCV cDNA in healthy human serum was successfully detected, demonstrating the feasibility of the developed device for the detection of cDNA in real biological samples. Additionally, simultaneous HIV/HCV cDNA detection on a single ACEL device employing a 2x2-array detection zone design. The cross-reactivity with other viral DNA was shown to be minimal due to the high specificity of the PNA probes used. Finally, the negative and positive samples from the patient's serum were tested and the results were in 100% agreement with the commercial kit based-on real-time PCR method, thus illustrating the high sensitivity and specificity of the developed sensor., (Copyright © 2021. Published by Elsevier B.V.)
- Published
- 2022
- Full Text
- View/download PDF
43. An origami paper-based peptide nucleic acid device coupled with label-free DNAzyme probe hybridization chain reaction for prostate cancer molecular screening test.
- Author
-
Kaewarsa P, Vilaivan T, and Laiwattanapaisal W
- Subjects
- Antigens, Neoplasm, Early Detection of Cancer, Humans, Male, Nucleic Acid Hybridization, DNA, Catalytic, Peptide Nucleic Acids, Prostatic Neoplasms diagnosis, Prostatic Neoplasms genetics
- Abstract
Prostate cancer associated 3 (PCA3) assay has been used to improve prostate cancer diagnosis and reduce unnecessary biopsies. In this work, we successfully developed a new PCA3 assay on an origami paper-based peptide nucleic acid device (oPAD). The PCA3 oPAD comprises an acrylic cassette and shutter slides to facilitate the molecular reaction and liquid control occurring on the paper surface. To quantify PCA3, a pyrrolidinyl peptide nucleic acid (acpcPNA) was immobilized onto the aldehyde-modified oPAD surface as a selective capture probe. A G-quadruplex (GQD) DNAzyme reporter probe was designed so that the PCA3 gene target binding triggered the hybridization chain reaction of the reporter probe, resulting in the accumulation of the GQD on the oPAD. The peroxidase activity of the GQD-hemin generated a deep green color of the oxidized ABTS substrate. Image analyses were performed in Adobe Photoshop CS6. The proposed oPAD was successfully applied in PCA3 detection ranges of 1-5 μM (r
2 = 0.982) with a limit of detection of 0.5 μM. Our proposed oPAD was demonstrated to measure PCA3 samples in both urine matrix and human cancer cell lines. The results reveal the great potential of our origami paper-based platform to be an alternative approach for facile, rapid, and low-cost detection of PCA3 in real samples., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier B.V. All rights reserved.)- Published
- 2021
- Full Text
- View/download PDF
44. Pyrrolidinyl peptide nucleic acids bearing hydroxy-modified cyclobutane building blocks: Synthesis and binding properties.
- Author
-
Ditmangklo B, Sittiwong W, Boddaert T, Vilaivan T, and Aitken DJ
- Subjects
- DNA, Complementary, RNA, Stereoisomerism, Cyclobutanes, Peptide Nucleic Acids
- Abstract
The conformationally constrained pyrrolidinyl PNA with a dipeptide consisting of an alternating nucleobase-modified D-proline and a cyclic β-amino acid "spacer" exhibited improved nucleic acid binding properties compared to the original PNA. The pyrrolidinyl PNA with the four-membered ring spacer (1S,2S)-2-aminocyclobutanecarboxylic acid (acbcPNA) are among the best performed members of the pyrrolidinyl PNA family. However, these PNA suffer some limitations such as aqueous solubility and non-specific interactions due to their extreme hydrophobicity. In the present work, a hydroxy group is introduced onto the cyclobutane ring spacer of the acbcPNA with the aim of decreasing its hydrophobicity. To this end, a Fmoc/tBu ether-protected 4-hydroxy-2-aminocyclobutanecarboxylic acid building block was synthesized and resolved by chiral HPLC. Each enantiomer was used to synthesize the hydroxy-modified acbcPNA employing Fmoc solid-phase peptide synthesis. DNA/RNA binding studies indicated that the introduction of the hydroxy group to the acbcPNA decreases the binding affinity toward complementary DNA and RNA while maintaining the sequence and directional specificity of unmodified acbcPNA. The hydrophobicity of the hydroxy-modified acbcPNA decreased with the number of hydroxy groups added as indicated by the decrease in the logP values. Only two modifications were sufficient to decrease the logP by an order of magnitude without excessively lowering the binding affinity nor the specificity. This work thus demonstrated that the specific structural modifications for this type of PNA model can be performed in a modular fashion, which paves the way toward the future realization of improving hydrophilicity and nucleic acid binding affinity as well as specificity., (© 2021 Wiley Periodicals LLC.)
- Published
- 2021
- Full Text
- View/download PDF
45. Paper-based sensor from pyrrolidinyl peptide nucleic acid for the efficient detection of Bacillus cereus.
- Author
-
Jirakittiwut N, Patipong T, Cheiwchanchamnangij T, Waditee-Sirisattha R, Vilaivan T, and Praneenararat T
- Subjects
- Oryza microbiology, Paper, Bacillus cereus isolation & purification, Biosensing Techniques methods, Food Microbiology, Peptide Nucleic Acids chemistry, Pyrrolidines chemistry
- Abstract
Bacillus cereus is one of the most common foodborne pathogens found in various kinds of staple foods such as rice and wheat. A rapid and accurate detection method for this pathogen is highly desirable for the sustainable production of relevant food products. While several classical and molecular-based detection methods are available for the identification of B. cereus, they suffered one or more limitations such as the requirement for a tedious and time-consuming process, less than ideal specificity, and the lack of portability. Herein, we developed the first paper-based sensing device that exhibits high species specificity with sufficiently low limit of detection for the visual detection of specific DNA sequences of B. cereus. The success is attributed to the strategic planning of fabrication in various dimensions including thorough bioinformatics search for highly specific genes, the use of the pyrrolidinyl peptide nucleic acid (PNA) probe whose selectivity advantage is well documented, and an effective PNA immobilization and DNA-binding visualization method with an internal cross-checking system for validating the results. Testing in rice matrices indicates that the sensor is capable of detecting and distinguishing B. cereus from other bacterial species. Hence, this paper-based sensor has potential to be adopted as a practical means to detect B. cereus in food industries., (© 2021. Springer-Verlag GmbH Germany, part of Springer Nature.)
- Published
- 2021
- Full Text
- View/download PDF
46. Fluorescent paper-based DNA sensor using pyrrolidinyl peptide nucleic acids for hepatitis C virus detection.
- Author
-
Teengam P, Nisab N, Chuaypen N, Tangkijvanich P, Vilaivan T, and Chailapakul O
- Subjects
- DNA, Hepacivirus genetics, Humans, Nucleic Acid Hybridization, Biosensing Techniques, Hepatitis C diagnosis, Peptide Nucleic Acids
- Abstract
A novel fluorescent paper-based DNA sensor employing a highly specific pyrrolidinyl peptide nucleic acid (acpcPNA) probe was developed for the sensitive and selective detection of hepatitis C virus (HCV). The acpcPNA was covalently immobilized onto partially oxidized cellulose paper via reductive alkylation between the amine and the aldehyde groups. The fluorescence-based detection was performed by monitoring the fluorescence signal response of a fluorescent dye that selectively binds to the single-strand region of the DNA target over the PNA probe employing a custom-made portable fluorescent camera gadget in combination with a smartphone camera. Under the optimal conditions, a linear relationship between the fluorescence change in the green channel and the amount of HCV DNA from 5 to 100 pmol with a correlation coefficient of 0.9956, and the limit of detection of 5 pmol were obtained for short synthetic oligonucleotides. The acpcPNA probe exhibited very high selectivity for the complementary oligonucleotides over the single-base-mismatched, two-base-mismatched, and non-complementary DNA targets. Benefitting from the signal amplification achieved through the numerous binding sites for the dye provided by the overhanging tail of long ssDNA target sequences, this system was successfully applied to detect the HCV complementary DNA (cDNA) obtained from clinical samples with satisfactory results. The proposed fluorescent paper-based sensor demonstrated a great potential to be used as a low-cost, simple, label-free, sensitive, and selective DNA sensor for point-of-care applications., (Copyright © 2021 Elsevier B.V. All rights reserved.)
- Published
- 2021
- Full Text
- View/download PDF
47. Investigation of key chemical species from durian peduncles and their correlations with durian maturity.
- Author
-
Charoensumran P, Pratumyot K, Vilaivan T, and Praneenararat T
- Abstract
The popularity and high price of durian make quality control in terms of ripeness very important, which in turn depends heavily on harvesting at an appropriate maturity stage. To date, reports on data-driven methods for maturity prediction are scarce, with many rather focusing on ripeness prediction. Herein, we report the first disclosure of key molecular markers in the liquid extract of durian peduncle that can be a predictive tool for maturity. Multiple chromatographic and spectroscopic techniques including TLC, HPLC, PS-MS, LC-MS/MS, and NMR, were used to characterize chemical profiles of the aqueous extracts from peduncles at different ages. Four compounds that show positive correlations with maturity were identified as sucrose, asparagine, arginine, and pipecolic acid, with asparagine as the most abundant species. This finding paves the way for more research of high impact such as the relationship between biochemical reactions in peduncle and pulp, and the development of accurate and non-destructive sensors for maturity prediction.
- Published
- 2021
- Full Text
- View/download PDF
48. Isothermal Detection of Canine Blood Parasite ( Ehrlichia canis ) Utilizing Recombinase Polymerase Amplification Coupled with Graphene Oxide Quenching-Based Pyrrolidinyl Peptide Nucleic Acid.
- Author
-
Yukhet P, Buddhachat K, Vilaivan T, and Suparpprom C
- Subjects
- Animals, DNA metabolism, Dogs, Ehrlichia canis genetics, Genes, Bacterial, RNA, Ribosomal, 16S chemistry, Ehrlichia canis isolation & purification, Graphite chemistry, Peptide Nucleic Acids chemistry, Pyrrolidines chemistry, Recombinases metabolism
- Abstract
Canine monocytic ehrlichiosis (CME), caused by transmitted Ehrlichia canis infection, is a major disease in dogs with worldwide distribution. Herein, a nucleic acid assay was established for the identification of E. canis infection employing a fluorescently labeled conformationally constrained pyrrolidinyl PNA probe (Flu-acpcPNA) designed to sequence-specifically target the 16S rRNA gene. The sensing principle is based on the excellent quenching ability of graphene oxide (GO) of the free PNA probe, that was diminished upon binding to the DNA target. The addition of DNase I improved the performance of the detection system by eliminating the nonspecific quenching capability of long-chain dsDNA and thus enhancing the fluorescence signaling. The assay was coupled with a recombinase polymerase amplification (RPA) technique, which could be performed under isothermal conditions (37 °C) without DNA denaturation and purification steps. The established method is simple to set up and execute, proving a rapid, specific, and sensitive detection of 16S rRNA gene of E. canis with a limit of detection at least 11.1 pM. This technique shows good potential for the visual detection of double-stranded DNA targets without the need for PCR or complicated instruments, which shows great promise for practical usage in resource limited areas.
- Published
- 2021
- Full Text
- View/download PDF
49. Selective enrichment of zein gene of maize from cereal products using magnetic support having pyrrolidinyl peptide nucleic acid probe.
- Author
-
Khadsai S, Seeja N, Rutnakornpituk M, Vilaivan T, Nakkuntod M, Suwankitti W, Kielar F, and Rutnakornpituk B
- Subjects
- DNA, Complementary analysis, Edible Grain genetics, Electrophoresis, Fluorescent Dyes chemistry, Magnetic Phenomena, Polymerase Chain Reaction, Spectrometry, Fluorescence, DNA, Plant analysis, Magnetite Nanoparticles chemistry, Peptide Nucleic Acids chemistry, Zea mays genetics, Zein genetics
- Abstract
Here, we describe DNA enrichment of the zein gene from maize using pyrrolidinyl peptide nucleic acid (PNA) immobilized on a magnetic solid support as a capture element. Magnetite nanoparticles (MNP) with a capacity of 373 pmolPNA/mg and coated with poly(N-acryloylglycine) (PNAG) showed a good response to magnetic field. The PNA probe immobilized on the MNP discriminated between non-complementary and complementary DNA using fluorophore-tagged DNA as a model. We applied this system for the enrichment of the zein gene from maize in eight cereal product samples. After DNA desorption from the MNP, and its amplification via polymerase chain reaction (PCR), gel electrophoresis indicated that only cereal samples containing the zein gene from maize yielded positive results, indicating a high binding specificity between the PNA used and the complementary DNA. This PNA-functionalized MNP is potentially useful as an effective nano-solid support for DNA enrichment from other samples., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)
- Published
- 2021
- Full Text
- View/download PDF
50. Amplification-free DNA Sensor for the One-Step Detection of the Hepatitis B Virus Using an Automated Paper-Based Lateral Flow Electrochemical Device.
- Author
-
Srisomwat C, Yakoh A, Chuaypen N, Tangkijvanich P, Vilaivan T, and Chailapakul O
- Subjects
- DNA, Viral genetics, Hepatitis B virus genetics, Humans, Nucleic Acid Amplification Techniques, Biosensing Techniques, Carcinoma, Hepatocellular, Liver Neoplasms
- Abstract
Until now, an electrochemical lateral flow assay (eLFA) capable of detecting nucleic acids has remained a challenge and has been scarcely explored because of its complicated multistep nature. Here, we report an automated paper-based eLFA device for the quantitative detection of the hepatitis B virus (HBV)-the major cause of liver cirrhosis and hepatocellular carcinoma (HCC). Using a time-delayed microfluidic strategy fabricated on paper, an automated and precisely sequenced solution transfer was enabled by single sample loading. A gold metallization strategy was employed for the signal-on electrochemical detection of the target DNA. Furthermore, a pyrrolidinyl peptide nucleic acid (so-called "acpcPNA") was used as a probe in this study because it offers higher specificity and yields lower background currents than those of traditional probes. Under optimal conditions, a broad dynamic range (10 pM to 2 μM) with an excellent detection limit (down to 7.23 pM) was achieved. The overall operation can be completed within 7 min of sample loading. The proposed sensor was successfully applied in HBV DNA detection in sera from patients without any amplification step (e.g., PCR) required, thus simplifying the operation further. Additionally, the results obtained from this present device are in accordance with the standard real-time PCR, thus supporting the accuracy of the method.
- Published
- 2021
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.