Jiang Xiongping* (Institute for Drug Control of People′s Liberation Army, Beijing 100071) Xu Danke, Liu Yaoqing, Ma Liren (Academy of Military Medical Sciences, Beijing 100850)
Abstract A chemiluminescent biosensor for nucleic acid was described. Gold surface was modified with N-Acetylcysteine to produce a self-assembled monolayer. A single layer film of biotinylated oligonucleotide probes was constructed by binding to a precursor layer of streptavidin which had been immobilized on modified gold surface covalently using carbodiimide hydrochloride(EDC) and N-hydroxysuccinimide(NHS). A sandwich solution hybridization was executed with immobilized deoxyribo-nucleic acid (DNA), target DNA and second biotinylated DNA probes. Then extravidin alkaline phosphatase which can dephosphorylate substrates AMPPD to produce stable intermediates that produce a measurable yield of light output was bound with second hybridized biotinylated DNA probes. And hepatitis B virus (HBV) DNA fragment was measured. The sensitivity of HBV DNA was obtained as 3×10-14 mol/L. Keywords Nucleic acid biosensor, chemiluminescence, hepatitis B virus deoxyribonucleic acid