title: Polythiophene derivative on quartz resonators for miRNA capture and assay.
abstract: 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.
authors.affiliation: School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798. alps@ntu.edu.sg bliedberg@ntu.edu.sg.
authors.forename: Al
authors.initials: A
authors.lastname: Palaniappan
authors.forename: Jamal Ahmed
authors.initials: JA
authors.lastname: Cheema
authors.forename: Deepa
authors.initials: D
authors.lastname: Rajwar
authors.forename: Gopal
authors.initials: G
authors.lastname: Ammanath
authors.forename: Liu
authors.initials: L
authors.lastname: Xiaohu
authors.forename: Lim Seng
authors.initials: LS
authors.lastname: Koon
authors.forename: Wang
authors.initials: W
authors.lastname: Yi
authors.forename: Umit Hakan
authors.initials: UH
authors.lastname: Yildiz
authors.forename: Bo
authors.initials: B
authors.lastname: Liedberg
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D006801:Humans; D035683:MicroRNAs / Q000032:analysis* / Q000097:blood / Q000302:isolation & purification*; D015394:Molecular Structure; D011108:Polymers / Q000737:chemistry*; D011791:Quartz / Q000737:chemistry*; D013876:Thiophenes / Q000737:chemistry*
chemical_list: D035683:MicroRNAs; D011108:Polymers; D013876:Thiophenes; D011791:Quartz; C066730:polythiophene