title: Direct electrocatalytic mRNA detection using PNA-nanowire sensors.
abstract: We report an electrochemical nucleic acids sensing system that exhibits high sensitivity and specificity when challenged with heterogeneous samples of RNA. The platform directly detects specific RNA sequences in cellular and clinical samples without any sample labeling or PCR amplification. The sensor features an electrode platform consisting of three-dimensional gold nanowires, and DNA or RNA hybridization is detected using an electrocatalytic reporter system. In this study, probes made of peptide nucleic acid (PNA) are used to detect a newly identified cancer biomarkera gene fusion recently associated with prostate cancer. The system is able to detect the fusion sequence with 100 fM sensitivity, and retains high sensitivity even in the presence of a large excess of non-complementary sequences. Moreover, the sensor is able to detect the fusion sequence in as little as 10 ng of mRNA isolated from cell lines or 100 ng total RNA from patient tissue samples. The PNA-nanowire nucleic acids sensor described is one of the first electrochemical sensors to directly detect specific mRNAs in unamplified patient samples.
authors.affiliation: Leslie Dan Faculty of Pharmacy, Department of Pharmaceutical Sciences, and Faculty of Medicine, Department of Biochemistry, University of Toronto, Ontario M5S 3M2, Canada.
authors.forename: Zhichao
authors.initials: Z
authors.lastname: Fang
authors.forename: Shana O
authors.initials: SO
authors.lastname: Kelley
mesh_terms: D001483:Base Sequence; D015415:Biomarkers / Q000032:analysis; D015374:Biosensing Techniques; D002384:Catalysis; D004566:Electrodes; D006046:Gold / Q000737:chemistry; D006367:HeLa Cells; D006801:Humans; D053770:Nanowires / Q000737:chemistry*; D020135:Peptide Nucleic Acids / Q000737:chemistry*; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000032:analysis*; D012680:Sensitivity and Specificity
chemical_list: D015415:Biomarkers; D020135:Peptide Nucleic Acids; D012333:RNA, Messenger; D006046:Gold