Author(s): Yang M, Li H, Javadi A, Gong S. Multifunctional mesoporous silica nanoparticles as labels for the preparation of ultrasensitive electrochemical immunosensors. Biomaterials. 2010 Apr;31(12):3281-6. doi: 10.1016/j.biomaterials.2010.01.033. Epub 2010 Feb 8. PMID 20116845
Labels based on mesoporous silica nanoparticles (MSN) loaded with mediator thionine (TH), enzyme horseradish peroxidase (HRP) and secondary anti-human IgG antibody (Ab(2)) were developed in order to improve the sensitivity and detection limit of an amperometric immunosensor. The sensitivity of the sandwich-type immunosensor using MSN-TH-HRP-Ab(2) as labels for human IgG detection was about 100 times higher than that using either MSN-TH-Ab(2) or MSN-HRP-Ab(2) as labels, indicating the high catalytic efficiency of HRP in the presence of mediator TH toward H(2)O(2). The immunosensor using MSN-TH-Ab(2) as labels exhibited a high sensitivity and showed a linear response within the range of 0.01-10 ng/mL human IgG. It also showed good reproducibility and selectivity and acceptable stability. These labels for immunosensors may provide many potential applications for the detection of different biomolecules.