Fast Synthesis of Cu₂O Hollow Microspheres and Their Application in DNA Biosensor of Hepatitis B Virus

Well dispersed Cu 2 O hollow microspheres consisted of Cu 2 O nanoparticles were quickly synthesized in aqueous solution at room temperature (25 °C) with polyvinylpyrrolidone (PVP) as surfactant. The influences of the reaction time, PVP amount and pH value of NaOH solution were studied. The formation mechanism of Cu 2 O hollow spheres is that, with the modification and steric effect of PVP molecules, Cu 2 O nanoparticles aggregate to form loose aggregations and then quickly transform to hollow spheres through Ostwald ripening. Formation of loose aggregations is the key to the fast synthesis of hollow spheres at low temperature. The application of Cu 2 O hollow microspheres in DNA biosensor was also investigated. The hollow Cu 2 O microspheres greatly enhance the immobilization of the DNA probe on the electrode surface and improve the sensitivity of DNA biosensors.