Applications Of Gold Nanoparticle Probes & CuS Film To Biosensor

Nanoparticles have become one of the appealing research fields, owing to their many peculiar property and their great high technology applied prospect. Recently nanotechnique has been applied into the field of biosensor and provides the development of biosensor with the infinite prospect. In sum, nanoparticles have been used to immobilize the bioactive substance, detect and amplify the signal, enrich and concentrate the analyte. In the first two parts of the work, Alkanethiololigonucleotide and goat-anti-human antibody modified with the colloidal gold were respectively used to detect the single nucleotide polymorphism (SNP) and human immunoglobulin G (IgG). In the last part, a capacitance immunosensor based copper sulfide membrane prepared by step-assembly was reported. The detailed materials are showing as following:In the first part, a novel method, which used antibody-colloidal gold conjugate and immunocomplex for improving the sensitivity of piezoelectric immunosensor through dual amplification on the base of self-assembly, was presented. Goat anti-human IgG firstly hybridized with the layer of staphylococcal protein A pre-assembled on Au-electrode of quartz crystal microbalance (QCM), resulting the sensing interface. After human IgG interacted with the sensing interface, the signal was amplified by antibody-colloidal gold conjugate and immunocomplex. To improve the sensitivity, the component of immunocomplex and the dilution ratio of antibody-colloidal gold conjugate were optimized. The results showed that the QCM immunosensor could quantitatively determine human IgG in the range of 10.9 ng/mL^-1 to 10.9μg/mL^-1;comparing to the ordinary piezoelectric immunosensor, an obviousimprovement in the sensitivity and detection limit is achieved in this method.In the second part, a padlock was designed to detect the single-base mutation in codon 12 of K-ras oncogeneo Only a perfect matchat the target region between the padlock and target strand allowed the circularization of the padlock probe in the presence of E. coli. Ligase. The linear concatameric product of RCA was finally obtained by