We have built porous gold nanostructure substrates with tunable plasmon resonances and explored to detect the interactions between biomolecules and molecular information by using localized surface plasmon resonance (LSPR) and surface enhanced Raman scattering (SERS). We have developed a system to fabricate SiO2 colloidal crystal films with excellent order, controllable thickness and large-area uniform. Size-tunable, aminated SiO2 colloidal crystal films have been fabricated so as to meet different needs. By controlling the reaction rate, deposition time and different reductants, AuCl4- has been reduced and deposited on the surface of SiO2 films to form a composite structure of gold nanoshells. Besides, plasmonic nanoparticles with different structures exhibit unique optical properties and SERS effects due to LSPR. We used high-quality, porous gold substrates as biological sensors to detect the influence under different experimental conditions on their LSPR and SERS properties. By adjusting the particle size and shape, we obtain the optimized substrates with excellent LSPR and SERS properties. Then, antibodies and some molecular ligands can be effectively immobilized on the porous layer surface of gold substrates, which can improve the immobilization efficiency and the stability of the immobilized antibodies and molecular ligands. And we can also investigate the fluid properties of target molecules in different holes. Furthermore, by using small molecule, antigen, and hemoglobin as typical detection systems, we detect a series of constants about small molecules and biological macromolecules. LSPR shift can help detect the binding process, such as antigen-antibody, ligand-biological macromolecules. By detecting the biomolecular interaction standard curve, binding constant, and detection sensitivity, we have learned the influence of nonspecific adsorption. From the SERS fingerprint spectrum, we have known the different molecules information owing to unique vibrational levels. And it turns out that the LSPR and SERS detections are complementary.

Biosensing based on porous gold nanostructure substrates with plasmonic tunability

256th National Meeting (2018)

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