Chemistry / Kimya

Permanent URI for this collectionhttps://hdl.handle.net/11147/4072

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Author: search.filters.author.Palaniappan, Al.Department: search.filters.department.İzmir Institute of Technology. Chemistry

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Now showing 1 - 2 of 2
  • Article
    Citation - WoS: 10
    Citation - Scopus: 12
    Tuning Pendant Groups of Polythiophene on Carbon Nanotubes for Vapour Classification
    (Elsevier Ltd., 2017) Tu, Meng-Che; Yıldız, Ümit Hakan; Thilini, Alahakoon; Wallace, Lim Tse Loong; Moochhala, Shabbir; Yıldız, Ümit Hakan; Palaniappan, Al.; Liedberg, Bo; 04.01. Department of Chemistry; 04. Faculty of Science; 01. Izmir Institute of Technology
    Poly(3-alkoxythiophene) (PT) with varying ratios of triethylamine and 1-methyl imidazole pendant groups and horizontally aligned single walled carbon nanotubes (SWCNT) are utilized in this study for volatile organic compounds (VOCs) classification. PTs with five different ratios of pendant groups are incorporated with SWCNT and are evaluated as chemiresistor arrays for analysis of VOCs such as ethanol, acetone, toluene, chloroform, isoprene and ethylene. Varying PT pendant groups yielded differential SWCNT current responses attributed to their chemical affinities for the VOCs tested. Principal component analysis (PCA) for vapour classification illustrated that the vapour responses are separable, thus, highlighting vapour discrimination ability of SWCNT with controlled ratios of PT pendant groups. The proposed methodology is a facile VOC classification approach for two main reasons; (i) PT could easily modified with various pendants groups containing appropriate chemical moieties for preferential interaction with various VOCs and (ii) increasing the number PTs with appropriate pendant group modifications would provide additional inputs to PCA thereby enabling capturing and assaying of a wide range of VOCs.
  • Article
    Citation - WoS: 14
    Citation - Scopus: 14
    Polythiophene Derivative on Quartz Resonators for Mirna Capture and Assay
    (Royal Society of Chemistry, 2015) Palaniappan, Al.; Yıldız, Ümit Hakan; Rajwar, Deepa; Ammanath, Gopal; Xiaohu, Liu; Seng Koon, Lim; Yi, Wang; Yıldız, Ümit Hakan; Liedberg, Bo; 04.01. Department of Chemistry; 04. Faculty of Science; 01. Izmir Institute of Technology
    A novel approach for miRNA assay using a cationic polythiophene derivative, poly[3-(3′-N,N,N-triethylamino-1′-propyloxy)-4-methyl-2,5-thiophene hydrobromide] (PT), immobilized on a quartz resonator is proposed. The cationic PT enables capturing of all RNA sequences in the sample matrix via electrostatic interactions, resulting in the formation of PT-RNA duplex structures on quartz resonators. Biotinylated peptide nucleic acid (b-PNA) sequences are subsequently utilized for the RNA assay, upon monitoring the PT-RNA-b-PNA triplex formation. Signal amplification is achieved by anchoring avidin coated nanoparticles to b-PNA in order to yield responses at clinically relevant concentration regimes. Unlike conventional nucleic acid assay methodologies that usually quantify a specific sequence of RNA, the proposed approach enables the assay of any RNA sequence in the sample matrix upon hybridization with a PNA sequence complementary to the RNA of interest. As an illustration, successful detection of mir21, (a miRNA sequence associated with lung cancer) is demonstrated with a limit of detection of 400 pM. Furthermore, precise quantification of mir21 in plasma samples is demonstrated without requiring PCR and sophisticated instrumentation.