Sensitive fluorescent detection of Staphylococcus aureus using nanogold linked CdTe nanocrystals as signal amplification labels

Miao, Tinging; Wang, Zhouping; Li, Shuang; Wang, Xin
March 2011
Microchimica Acta;Mar2011, Vol. 172 Issue 3/4, p431
Academic Journal
sensitive fluorescent assay was developed for the detection of DNA specifically for Staphylococcus aureus. A sandwich-type detection system was fabricated by first immobilizing biotinylated capture DNA on avidin-modified wells of microplates, then hybridizing the capture DNA with one end of the target DNA, and then recognizing the other end of the target DNA with a signal probe labeled with CdTe nanocrystals and gold nanoparticles (Au-NPs) at the 3′- and 5′-terminus, respectively. Hybridization was monitored by measuring the fluorescent intensity of the assembly. The experimental results demonstrated that the incorporation of Au-NPs in this detection system can significantly enhance the sensitivity and the selectivity because a single Au-NP can be loaded with hundreds of signal DNA probe strands modified with CdTe nanocrystals. Under the optimized conditions, a detection limit of 10 fmol of DNA per L can be achieved and at least 50 colony forming units of Staph. aureus per mL of sample can be detected. The method was assessed by analyzing real samples, and it was validated by comparing it to an official standard method. [Figure not available: see fulltext.]


Related Articles

  • Selective Synthesis of Wurtzite CdSe Nanorods and Zinc Blend CdSe Nanocrystals through a Convenient Solvothermal Route. Yong Liu; Hua-Yu Qiu; Yao Xu; Dong Wu; Mei-Jiang Li; Jian-Xiong Jiang; Guo-Qiao Lai // Journal of Nanoparticle Research;Oct2007, Vol. 9 Issue 5, p745 

    Abstract  By simply changing the reactants’ compositions, wurtzite CdSe nanorods and zinc blend CdSe nanoparticles were selectively synthesized through a convenient solvothermal route with the reaction of cadmium nitrate (Cd(NO3)2 4H2O), hydrazine hydrate (N2H4 H2O), and Se in...

  • Microcavity strongly doped with CdSe nanocrystals. Rabaste, S.; Bellessa, J.; Bonnand, C.; Plenet, J. C.; Spanhel, L. // European Physical Journal B -- Condensed Matter;Nov2004, Vol. 42 Issue 1, p47 

    The fabrication and the study of sol gel-microcavities strongly doped with CdSe nanocrystals are presented. The Fabry-Perot microcavities are formed by a Distributed Bragg Reflector covered with a CdSe doped active layer and a silver mirror. These microcavities are studied with reflectometry...

  • Synthesis and spectroscopic study of high quality alloy CdxZn1-xS nanocrystals. Sadhu, Suparna; Patra, Amitava // Journal of Chemical Sciences;Nov2008, Vol. 120 Issue 6, p557 

    In the present study, we report the synthesis of high quality CdxZn1-xS nanocrystals alloy at 150°C with changing the composition. The shifting of absorption and emission peak in shorter wavelength is obtained with increasing the mole fraction of zinc. The quantum yield (QY) value decreases...

  • Optical characterization of CdSe/Dy-doped silica matrices. Jyothy, P.; Rejikumar, P.; Vinoy, Thomas; Kartika, S.; Unnikrishnan, N. // Pramana: Journal of Physics;Nov2010, Vol. 75 Issue 5, p999 

    Cadmium selenide nanocrystals along with dysprosium ions are doped in silica matrices through sol-gel route. The optical bandgap and size of the CdSe nanocrystals are calculated from the absorption spectrum. The size of the CdSe nanocrystallites is also evaluated from the TEM measurements. The...

  • Impedance spectroscopy investigation of electron transport in solar cells based on blend film of polymer and nanocrystals. Huang, Wenbo; Peng, Junbiao; Wang, Li; Wang, Jian; Cao, Yong // Applied Physics Letters;1/7/2008, Vol. 92 Issue 1, p013308 

    Bulk heterojunction solar cells, consisting of the active film of poly[2-methoxy,5-(2-ethylhexoxy)-1,4-phenylene vinylene] (MEH-PPV) doped with cadmium selenium (CdSe) nanoparticles, were fabricated and investigated using impedance spectroscopy (IS) technique. The spectroscopy displayed a...

  • Photostability of CdSe-based nanocrystalline structures used to visualize biological tissues. Osipovich, V.; Yashin, K.; Terpinskaya, T.; Zhavnerko, G.; Chubenko, E.; Petrovich, V.; Petrova, E. // Journal of Applied Spectroscopy;Mar2013, Vol. 80 Issue 1, p93 

    The structure, fluorescence parameters, and photostability of nanocrystalline CdSe and CdSe/ZnS intended for biomedical applications are examined. The photostability of nanocrystalline CdSe/ZnS with different functional and protective coatings is studied. The possibility of using semiconductor...

  • Manipulation of colloidal gold nanoparticles in the evanescent field of a channel waveguide. Ng, L. N.; Ng, L.N.; Zervas, M. N.; Zervas, M.N.; Wilkinson, J. S.; Wilkinson, J.S.; Luff, B. J.; Luff, B.J. // Applied Physics Letters;4/10/2000, Vol. 76 Issue 15 

    Colloidal gold spheres of radius 10 nm are reported to move forward in water, under the influence of radiation pressure forces, due to the evanescent field at the surface of an optical channel waveguide. The velocity is linearly dependent upon the optical power in the waveguide, acquiring a...

  • A DNA-based method for rationally assembling nanoparticles into macroscopic materials. Mirkin, Chad A.; Letsinger, Robert L. // Nature;8/15/1996, Vol. 382 Issue 6592, p607 

    Describes a method for assembling colloidal gold nanoparticles rationally and reversibly into macroscopic aggregates.

  • A Subtractively Optimized DNA Microarray Using Non-sequenced Genomic Probes for the Detection of Food-Borne Pathogens. Jin Yong Lee; Byoung Chan Kim; Kwan Jong Chang; Joo-Myung Ahn; Jee-Hoon Ryu; Hyo-Ihl Chang; Man Bock Gu // Applied Biochemistry & Biotechnology;May2011, Vol. 164 Issue 2, p183 

    In this study, we present the successful detection of food-borne pathogens using randomly selected non-sequenced genomic DNA probes-based DNA microarray chips. Three food-borne pathogens, Staphylococcus aureus, Salmonella enterica subsp. enterica serovar Typhimurium ( S. Typhimurium), and...


Other Topics