Marshall Laboratory of Biomedical Engineering, International Cancer Center, Laboratory of Evolutionary Theranostics (LET), School of Biomedical Engineering, Shenzhen University Health Science Center, Shenzhen, 518060, China.
Chem Commun (Camb). 2020 May 5;56(36):4942-4945. doi: 10.1039/d0cc01086c.
The detection of prostate specific antigen (PSA) is extremely important for the early diagnosis of prostate cancer. Herein, we report a dual-round signal amplification strategy for colorimetric/fluorescence/photoacoustic triple read-out detection of PSA using a silica coated Au@Ag core-shell nanorod (denoted Au@Ag@SiO2) based enzyme-linked immunosorbent assay (ELISA) system. In the presence of PSA, monoclonal primary antihuman PSA antibody (Ab1) captured PSA and was subsequently recognized by the secondary antihuman PSA detection antibody (Ab2) which was conjugated with glucose oxidase (GOx) functionalized magnetic beads (MBs) for signal amplification, then GOx catalyses the addition of glucose to generate hydrogen peroxide that etches the silver layer in Au@Ag@SiO2, thus producing abundant Ag+ to realize the second signal amplification. With the degradation of the silver layer, an obvious color change (green-to-pink) of the Au@Ag@SiO2 solution could be observed by the naked eye and its surface plasmon resonance (SPR) absorption had a red-shift, enhancing photoacoustic signal read-out at 780 nm. Additionally, the released Ag+ was caught by a Ag+-fluorescent probe (Ag+-FP) for enhanced fluorescence signal read-out. These results suggested that this ELISA system achieves a triple read-out detection of PSA. This work provides a promising strategy for multiple read-out detection of biomarkers, which has great potential in clinical diagnosis.
前列腺特异性抗原（PSA）的检测对前列腺癌的早期诊断极为重要。在此，我们报告了一种使用基于硅涂层金@银核壳纳米棒（表示为 Au@Ag@SiO2）的酶联免疫吸附测定（ELISA）系统的比色/荧光/光声三重读出检测 PSA 的双轮信号放大策略。在 PSA 的存在下，单克隆抗人 PSA 抗体（Ab1）捕获 PSA，随后被与葡萄糖氧化酶（GOx）功能化磁性珠（MBs）偶联的抗人 PSA 检测抗体（Ab2）识别，以进行信号放大，然后 GOx 催化葡萄糖的添加以生成可蚀刻 Au@Ag@SiO2 中的银层的过氧化氢，从而产生丰富的 Ag+来实现第二轮信号放大。随着银层的降解，Au@Ag@SiO2 溶液的颜色（绿色变为粉红色）可通过肉眼观察到明显变化，其表面等离子体共振（SPR）吸收发生红移，增强了 780nm 处的光声信号读出。此外，释放的 Ag+被 Ag+-荧光探针（Ag+-FP）捕获，以增强荧光信号读出。这些结果表明，该 ELISA 系统实现了 PSA 的三重读出检测。这项工作为生物标志物的多重读出检测提供了一种有前途的策略，在临床诊断中具有很大的潜力。
