Ultrasensitive detection of IgE levels based on magnetic nanocapturer linked immunosensor assay for early diagnosis of cancer

Rapid and accurate detection of immunoglobulin E (IgE) in serum and reduction of serum dosage are of great significance for clinical detection. Herein, we described a rapid magnetic separation of IgE from patient serum based on Fe₃O₄@SiO₂-NTA@026 sdab as the capture probe and multiple horseradish peroxidase (HRP)-labeled antibodies linked gold nanoparticles (AuNPs) as chemiluminescence (CL) signal amplifier for ultrasensitive detection of total IgE. Results showed that the limit of detection of our immunosensor system in serum samples was 0.03 kU/L, which is lowest in comparison with current methods, and far lower than that of ImmunoCAP for IgE detection (0.1 kU/L). Furthermore, our immunosensor possessed satisfied repeatability and accuracy, as well as good stability. In comparison with the ImmunoCAP for the quantitative detection of IgE, highly consistent results were achieved in 20 serum samples. Specially, this method was also successfully utilized for assessing the IgE traces in breast cancer patients, which provides a new idea for the diagnosis of early cancer. Therefore, we believe that such versatile immunosensor will offer an alternative method for the on-site monitoring and determination of various IgE-related diseases.