title: Oligonucleotide-gold nanoparticle networks for detection of Cryptosporidium parvum heat shock protein 70 mRNA.
abstract: We report on a novel strategy for the detection of mRNA targets derived from Cryptosporidium parvum oocysts by the use of oligonucleotide-gold nanoparticles. Gold nanoparticles are functionalized with oligonucleotides which are complementary to unique sequences present on the heat shock protein 70 (HSP70) DNA/RNA target. The results indicate that the presence of HPS70 targets of increasing complexity causes the formation of oligonucleotide-gold nanoparticle networks which can be visually monitored via a simple colorimetric readout measured by a total internal reflection imaging setup. Furthermore, the induced expression of HSP70 mRNA in Cryptosporidium parvum oocysts via a simple heat shock process provides nonenzymatic amplification such that the HSP70 mRNA derived from as few as 5 x 10(3) purified C. parvum oocysts was successfully detected. Taken together, these results support the use of oligonucleotide-gold nanoparticles for the molecular diagnosis of cryptosporidiosis, offering new opportunities for the further development of point-of-care diagnostic assays with low-cost, robust reagents and simple colorimetric detection.
authors.affiliation: Department of Bioengineering, Rice University, Houston, Texas 77005, USA.
authors.forename: David J
authors.initials: DJ
authors.lastname: Javier
authors.forename: Alejandro
authors.initials: A
authors.lastname: Castellanos-Gonzalez
authors.forename: Shannon E
authors.initials: SE
authors.lastname: Weigum
authors.forename: A Clinton
authors.initials: AC
authors.lastname: White
authors.forename: Rebecca
authors.initials: R
authors.lastname: Richards-Kortum
mesh_terms: D000818:Animals; D003457:Cryptosporidiosis / Q000175:diagnosis* / Q000469:parasitology; D016785:Cryptosporidium parvum / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D016054:DNA, Protozoan / Q000235:genetics / Q000378:metabolism; D006046:Gold / Q000737:chemistry; D018840:HSP70 Heat-Shock Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D053758:Nanoparticles / Q000737:chemistry; D009841:Oligonucleotides / Q000737:chemistry / Q000235:genetics; D033661:Oocysts / Q000254:growth & development / Q000378:metabolism; D012333:RNA, Messenger / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D012680:Sensitivity and Specificity
chemical_list: D016054:DNA, Protozoan; D018840:HSP70 Heat-Shock Proteins; D009841:Oligonucleotides; D012333:RNA, Messenger; D006046:Gold