Glial fibrillary acidic protein (GFAP) is one of the discriminative biomarkers for diagnosing traumatic brain injury (TBI), and accurate determination of GFAP is clinically significant. In this study, a novel fluorescence immunoassay system was designed. We encapsulated carbon dots with a high fluorescence quantum yield (QY = 92.5%) inside silicon nanocapsules to serve as fluorescent markers. These markers were then integrated with the streptavidin (SA)-biotin biomagnification system and immunomagnetic separation technology for the sensitive detection of GFAP. Based on the signal cascade amplification effect of the silicon nanocapsules and SA-biotin, the fluorescence signal of the SA-biotin-modified immunofluorescence nanocapsules increased 3.6-fold compared to the carbon dot-based immunoprobe. The fluorescence immunoassay system was constructed for GFAP using SA-biotin-modified immunocapsules as the sensing probe and immunomagnetic nanoparticles as the immunorecognition probe. The fluorescence immunoassay system can specifically and ultra-sensitively quantify GFAP in blood samples, with a detection range of 10 pg/mL–10 ng/mL and detection limits of 3.2 pg/mL (serum) and 3.6 pg/mL (plasma). Moreover, the fluorescence immunoassay system exhibited prominent recoveries of 99.4%–100.4% (phosphate buffered saline), 96%–102.6% (serum), and 93.2%–110.2% (plasma), with favorable specificity and excellent stabilization. The novel fluorescence immunoassay system provides a new approach to the clinical analysis of GFAP and may serve as a potential tool for screening and diagnosing TBI.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |