报道了空间稳定的表面增强拉曼散射(SERS)标记的金纳米棒探针在免疫检测方面的应用.该探针是将拉曼活性分子4-巯基苯甲酸和生物亲和性高分子α-巯基-ω-羧基聚乙二醇共吸附于金纳米棒表面而制得.其中,聚乙二醇高分子链为探针提供保护作用和空间稳定,使之可以耐受较苛性的条件;其端位的羧基与抗体等靶向实体结合,从而赋予探针检测识别功能.当探针检测待测抗原时(通过固体基底上的捕获抗体、待测抗原和探针上的抗体之间的特异性结合,形成经典"三明治"夹心结构),探针上4-巯基苯甲酸的SERS信号就能示踪出这种识别.该探针对单组分抗原的检出浓度能低至1×10-9 mg·mL-1.
The immunoassay application of sterically stabilized,surface-enhanced Raman scattering(SERS)-tagged Au nanorod(NR) probes was reported.The probes were prepared by coadsorbing Raman-active molecule 4-mercaptobenzoic acid and biocompatible α-mercapto-ω-carboxyl polyethylene glycol onto the surfaces of Au NRs.The long PEG chain provides both protection and steric stabilization to the probes so that they are able to survive in adverse condition;meanwhile,its terminal carboxyl group binds target entity such as antibody,which imparts detection/recognition functionality to the probes.When the probe recognizes antigen(through the classical "sandwich" structure that was formed due to the highly binding specificity among capture antibody on a solid substrate,detected antigen,and antibody on the probe),the recognition is signaled by the SERS signals of the 4-mercaptobenzoic acid.The detection limit of the Au NR probes,for a single component antigen,was as low as 1×10-9 mg?mL-1.