U sing Gold nanoparticles as a solid carrier for lum inant molecules as a biocompatible label

Gold nanoparticles (GNPs) are very attrac tive labels due to their special physical and chemical prope rties such as ease of sy nthesis, sim plicity of conjugation a nd excellent biocompati bility [۱]. Their unique optical properties in h aving very low photob leaching an d blinking make them ideal carrie rs for optic al biosensors. Two approaches have been developed for GNPs based chemiluminescent bios ensors. GNP s can be us ed as chemil uminescent labels to am plify the detection of proteins and DNA[۲]. Also, th ey can be used as solid carrier for chemiluminescent molecules t o amplify t he detection of biomolec ules[۳].Gold nanoparticles were synthesis by reducing gold ions into solid gold. T his was done by using hydrogen tetrachloroa urate (HAu Cl۴) as source of gold ions and trisodium c itrate (Na۳C ۶H۵O۷) as reduction agent.Lumi nol and secondary antibody were immobilizedafter carbo xylation of the GNPs su rface.In the present work, by co-im mobilization of luminol and a seco ndary antibody on GN Ps we established a labeled antibody for detecti on of hepatitis B surfac e antigen in human serum. In the presence of h ydrogen peroxide as an oxidant, a stable an d efficient c hemilumine scent signal was obtained when lu minol molecules and secondary antibodies wer e co-immobilized on the GNP. Limit of detection in this s ystem is ۱۴ pg/ml. The process used in this report seems to be promising a new approach for establishment of a nan oparticle bas ed biosensor.

کلیدواژه ها:

gold nanoparticle s ، chemilum inescence ، luminol ، hep atitis B surface antigen