Wu Long, Li Xuepu, Shao Kang, Ye Shiyi, Liu Chen, Zhang Chenjun, Han Heyou
State Key Laboratory of Agricultural Microbiology, College of Science, Huazhong Agricultural University, Wuhan 430070, PR China.
State Key Laboratory of Agricultural Microbiology, College of Science, Huazhong Agricultural University, Wuhan 430070, PR China.
Anal Chim Acta. 2015 Aug 5;887:192-200. doi: 10.1016/j.aca.2015.06.024. Epub 2015 Aug 6.
Boosting the detection sensitivity of enzyme-linked immunosorbent assay (ELISA) is significant to the early clinical diagnosis of various diseases. Here, we developed a versatile immunosensor using silica nanospheres as carriers for sensitive detection of porcine circovirus type 2 (PCV2) antibody. With HRP enzyme covalently immobilized on the silica nanospheres and CdSe nanocrystals embedded inside, these signal probes were successfully utilized in the sensitive detection of PCV2 antibody by ELISA, fluorometry and square-wave voltammetry (SWV). To further demonstrate the performance of the immunosensor, Human IgG (HIgG) was used as a model analyte. Since more HRP and CdSe QDs were loaded, 5-, 200- and 400-fold enhancements in amplified ELISA, fluorometry and voltammetry responses for HIgG could be achieved compared to conventional ELISA. The respective detection limits of theses methods for HIgG were 3.9, 0.1 and 0.05 ng mL(-1) with a RSD below 5% for amplified ELISA, fluorescence and SWV measurements. Additionally, a 100-fold improvement was obtained in the detection sensitivity for PCV2 antibody immunoassay. The versatile immunosensor exhibits good sensitivity, stability and reproducibility, suggesting its potential applications in clinical diagnostics.
提高酶联免疫吸附测定（ELISA）的检测灵敏度对于各种疾病的早期临床诊断具有重要意义。在此，我们开发了一种通用免疫传感器，使用二氧化硅纳米球作为载体，用于灵敏检测猪圆环病毒2型（PCV2）抗体。通过将辣根过氧化物酶（HRP）共价固定在二氧化硅纳米球上，并将硒化镉（CdSe）纳米晶体嵌入其中，这些信号探针成功用于通过ELISA、荧光法和方波伏安法（SWV）灵敏检测PCV2抗体。为了进一步证明该免疫传感器的性能，使用人免疫球蛋白G（HIgG）作为模型分析物。由于加载了更多的HRP和CdSe量子点，与传统ELISA相比，针对HIgG的放大ELISA、荧光法和伏安法响应可分别提高5倍、200倍和400倍。这些方法对HIgG的各自检测限分别为3.9、0.1和0.05 ng mL-1，放大ELISA、荧光和SWV测量的相对标准偏差低于5%。此外，PCV2抗体免疫测定的检测灵敏度提高了100倍。该通用免疫传感器具有良好的灵敏度、稳定性和重现性，表明其在临床诊断中的潜在应用价值。
