Detection of Hepatitis B Virus Deoxyribonucleic Acid Based on Gold Nanoparticle Probe Chip

A nanoparticle-based bio-barcode amplification (BCA) approach was developed for the sensitive detection of hepatitis B virus (HBV) DNA. The BCA approach employed two sets of particles: (1) two-component oligonucleotide-modified gold nanoparticles (AuNPs) : one oligonuc-leotide probe called signal probe (barcode DNA) is partial complementary with the target sequence of HBV DNA and another one called detection probe is partial complementary with the signal probe; (2) single component oligonucleotide modified magnetic microparticles (MMPs). In the presence of the target molecule, the gold nanoparticles and magnetic particles formed sandwich hybrids. Along with the isolation of sandwiched hybrids from the sample using a magnet, non-specific bound gold nanoparticles were removed, ensuring that only target-bound gold nanoparticles were collected. Subsequently, the bar-code DNAs were dehybridized from the gold nanoparticle by using the dithiothreitol (DTT). The detection probe with AuNP mixed with bar-code DNA solution was then added to a bar-code capture DNA-modified chip, and the spots on chip were labeled with bar-code DNA strands and AuNP probes. Finally, the scanometric detection of silver stain was introduced to further amplify the signal. The results showed that it was possible in a format that offers low fmol/L (10(-15) mol/L) sensitivity in the detection of HBV DNA sample and there is a good linear relationship between target concentration and spot intensity on chip. The detection of the assay could be fulfilled within 1.5 h. The method could provide a new generation of diagnostic assays for HBV or the other infectious disease.