Fabrication Of Ordered Sers Substrates And Their Application In Protein Detection

The gold and silver nanoparticles have many advantageous features such aseasiness in synthesis, uniform size and good stability. Due to these advantages thegold and silver nanoparticles can be applied to prepare a variety of activesurface-enhanced Raman scattering (SERS) substrates. The monodisperse colloidalparticles are usually used to prepare ordered periodic templates composed by closelypacked colloidal particles by the self-assembly technique. The merits of SERS aresuper sensitivity, high selection and water resistance, making it one of the mostpopular current detection techniques. The major contributions of this work are asfollows:(1) We fabricated nano-engineered substrates composed of micropatterned Aunanoparticles and protein dots, which can be used for the SERS detection ofthe immunocomplex. This design includes a simple and effective substratefabrication technique, and provides a quantitative analysis of atto610-biotinwith the lowest detection concentration of100pg/mL. This is comparable tothe sensitivity of traditional optical biosensor methods.(2) We fabricated SERS substrates and antibody/avidin alternating arraymicrostructures. The microstructures have a stable protective surface layer(polystyrene and BSA), and the polystyrene can be removed just before theimmune response. This design can maintain the activity of antibody/avidinand be more convenient for practical applications in bioassay. (3) We fabricated a kind of composite substrates with gold and silvernanoparticles. The substrates have excellent enhancement capability for SERSdetection. The obtained substrates contain two kinds of nanoparticles andbeyond the limit of previous studies that mostly focused on the assembly ofsingle metal nanoparticles.