Study On Biosensors Based On Amplification Of Nanoparticals

With the rapid development of nanotechnologies, nanometer materials with unique optical and electrical properties have been widely used in bioanalysis. Three novel biosensors have been developed signal amplification of nanoparticals for the detection of DNA, adenosine and Ramos, respectively.1. Metal cadmium has been encapsulated in the apoferritin cavity by using dissociation and reconstitution characteristics at different pH of apoferritin. Au NPs were incorporated with marker-loaded apoferritin NPs. The conjugates were used as probe for DNA detection. With the dual-amplicification of Au NPs and marker-loaded apoferritin NPs, the sensor has high sensivity. Under the optimum conditions, the linear range was from 3.0 10 16 to 1.0 10 14 M and the detection limit was 5.1 10 17 M.2. A aptasensor for the assay of adenosine based on signal probe with ruthenium(II) modified Au nanoparticles was developed. Ru(II) complex were bound on Au NPs, and conjutaed with signal DAN to form the aptamer recognition probe. By using the specific recognization of aptamer and adenosine, the adenosine molecule could be detected. Take advantages of signal amplification of Au NPs, the sensor has exhibited good sensitivity. Under the optimum conditions, the linear range for the detection of adenosine was from 6.0×10-12 to 1.0×10-10 mo1·L-1. The sensor also exhibited excellent selectivity. 3. A sensitive and stable aptasensor for the assay of tumor cells based on signal amplification with novel ruthenium(II) covalently doped silica nanoparticles (Si NPs) was developed. Take advantages of signal amplification and high stability of the covalently doped Si NPs, the sensor has exhibited not only good sensitivity but also excellent stability. Under the optimum conditions, the linear range was from 100 to 2000 cells mL-1 and the detection limit was 100 cells mL-1 for the Ramos cells. The sensor has exhibited excellent selectivity and reproducibility.