title: Carbon Nanodot-Decorated Ag@SiO2 Nanoparticles for Fluorescence and Surface-Enhanced Raman Scattering Immunoassays.
abstract: A novel immunoassay protocol was demonstrated by the combination of fluorescent carbon nanodots (CNDs) and Ag@SiO2 surface-enhanced Raman scattering (SERS) tag nanoparticles into ensembles for a bifunctional nanoplatform. The CND-decorated Ag@SiO2 nanoparticles were constructed for sensitive fluorescence and SERS immunoassays. The silica shell thickness and amount of Ag@SiO2 nanoparticles were optimized for availability of strong fluorescence emission. The considerably large Raman scattering cross section of in situ-generated actual Raman reporter, 4,4'-dimercaptoazobenzene, from the apparent reporter p-aminothiophenol modified on the surfaces of Ag nanoparticles upon illumination of laser compensated for the reduction of SERS signals resulting from silica coating to a great degree. The antibody-modified bifunctional nanoparticles were captured by antibody-modified quartz slides in the presence of antigens in the sandwich structures for fluorescence and SERS immunoassays. The bifunctional nanoparticles could be used not only as bimodal probes for biodetection but also as bimodal tracers for bioimaging.
authors.affiliation: Key Laboratory of Mesoscopic Chemistry (Ministry of Education), State Key Laboratory of Coordination Chemistry, Collaborative Innovation Center of Chemistry for Life Sciences, and School of Chemistry and Chemical Engineering, Nanjing University , Nanjing, Jiangsu 210023, P. R. China.|Department of Applied Chemistry and Environmental Engineering, Bengbu College , Bengbu, Anhui 233030, P. R. China.
authors.forename: Xianfeng
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Mesoscopic Chemistry (Ministry of Education), State Key Laboratory of Coordination Chemistry, Collaborative Innovation Center of Chemistry for Life Sciences, and School of Chemistry and Chemical Engineering, Nanjing University , Nanjing, Jiangsu 210023, P. R. China.
authors.forename: Xuezhong
authors.initials: X
authors.lastname: Du
mesh_terms: D002244:Carbon / Q000737:chemistry*; D007118:Immunoassay / Q000379:methods*; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D012822:Silicon Dioxide / Q000737:chemistry*; D012834:Silver / Q000737:chemistry*; D013050:Spectrometry, Fluorescence; D013056:Spectrophotometry, Ultraviolet; D013059:Spectrum Analysis, Raman / Q000379:methods*; D055672:Static Electricity
chemical_list: D012834:Silver; D002244:Carbon; D012822:Silicon Dioxide
keywords: SERS; carbon nanodot; core@shell nanoparticle; fluorescence; immunoassay