Jou, A.F.-J.A.F.-J.JouLu, C.-H.C.-H.LuOu, Y.-C.Y.-C.OuWang, S.-S.S.-S.WangHsu, S.-L.S.-L.HsuWillner, I.I.WillnerHo, J.-A.A.J.-A.A.HoJA-AN ANNIE HO2018-09-102018-09-102015http://www.scopus.com/inward/record.url?eid=2-s2.0-84918786646&partnerID=MN8TOARShttp://scholars.lib.ntu.edu.tw/handle/123456789/391307The microRNA, miR-141, is a promising biomarker for prostate cancer. We implement here a two-step sensing platform for the sensitive detection of miR-141. The first step involves the use of semiconductor CdSe/ZnS quantum dots (QDs) modified by FRET quencher-functionalized nucleic acids, that include the recognition sequence for miR-141 and a telomerase primer sequence for the second step of the analytical platform. Subjecting the probe-modified QDs to miR-141, in the presence of duplex specific nuclease, DSN, leads to the formation of a miR-141/probe duplex and to its DSN-mediated cleavage, while regenerating the miR-141. The DSN-induced cleavage of the quencher units leads to the activation of the fluorescence of the QDs, thus allowing the optical detection of miR-141 with a sensitivity corresponding to 1.0 × 10-12 M. The nucleic acid residues associated with the QDs after cleavage of the probe nucleic acids by DSN act as primers for telomerase. The subsequent telomerase/dNTPs-stimulated elongation of the primer units forms G-quadruplex telomer chains. Incorporation of hemin in the resulting G-quadruplex telomer chains yields horseradish peroxidase-mimicking DNAzyme units, that catalyze the generation of chemiluminescence in the presence of luminol/H2O2. The resulting chemiluminescence intensities provide a readout signal for miR-141, DL = 2.8 × 10-13 M. The first step of the sensing platform is non-selective toward miR-141 and the resulting fluorescence may be considered only as an indicator for the existence of miR-141. The second step in the sensing protocol, involving telomerase, provides a selective chemiluminescence signal for the existence of miR-141. The two-step sensing platform is implemented for the analysis of miR-141 in serum samples from healthy individuals and prostate cancer carriers. Impressive discrimination between healthy individuals and prostate cancer carriers is demonstrated. This journal is ? The Royal Society of Chemistry 2015.[SDGs]SDG3Biomolecules; Chains; Chemiluminescence; Diseases; Fluorescence; Probes; RNA; Signal detection; Urology; Chemiluminescence intensity; Duplex-specific nuclease; Healthy individuals; Horse-radish peroxidase; Optical detection; Recognition sequence; Semiconductor CdSe/ZnS quantum dots; Sensitive detection; Semiconductor quantum dotsjournal article10.1039/c4sc02104e