DIRECT DETECTION OF DISEASE BIOMARKERS IN CLINICAL SPECIMENS USING CATIONIC NANOPARTICLE-BASED ASSAYS & VERSATILE AND GREEN METHODS FORSYNTHESIS OF ANISOTROPIC SILVER NANOSTRUCTURES

摘要

A gold nanoparticle-based assay for the detection of a target molecule, such as Hepatitis C Virus (HCV) RNA in serum samples, that uses positively charged gold nanoparticles (AuNPs) in solution based format. The assay has been tested on 74 serum clinical samples suspected of containing HCV RNA, with 48 and 38 positive and negative samples respectively. The developed assay has a specificity and sensitivity of 96.5% and 92.6% respectively. The results obtained were confirmed by Real-Time PCR, and a concordance of 100% for the negative samples and 89% for the positive samples has been obtained between the Real-Time PCR and the developed AuNPs based assay. Also, a purification method for the HCV RNA has been developed using HCV RNA specific probe conjugated to homemade silica nanoparticles. These silica nanoparticles have been synthesized by modified Stober method. This purification method enhanced the specificity of the developed AuNPs assay. The method can detect a target molecule, such as HCV RNA in serum, by employing modified silica nanoparticles to capture the target from a biological sample followed by detection of the captured target molecule using positively charged AuNPs. The assay is simple, cheap, sensitive and specific. Another aspect of the invention is anisotropic silver nanoparticles and methods of their use.