Highly sensitive optoelectrical biosensor for multiplex allergy diagnosis

Compact multiplexed biosensors systems hold great potential for diagnosis of diseases where the detection of multiple biomarkers is required. Hypersensitivity Immunoglobulin E mediated syndromes are primary immunodeficiency disorders associated with sensitization to allergens. Assessing immunoglobulin E (IgE) sensitization to allergens is an important strategy for allergy diagnosis. Here, we report for the first time a reliable, flexible and cost-effective optoelectrical biosensor system for the simultaneous determination of total and allergen-specific IgE and IgG, antibodies using an immunogold-silver signal amplification method. The biosensor was constructed on a regular digital versatile disc (DVD) to immobilize a panel of 12 allergen extracts or pure proteins in microarray format, as a proof of concept. The multiplexed biosensor showed a limit of detection of 0.26 IU/mL (624 pg/mL) and 14 ng/mL for IgE and IgG antibodies, respectively. The system was successfully applied in a cohort of 127 human serum samples, showing good sensitivity (97.6%) as well as specificity (85.7%), and an excellent area under the curve (AUC) value was found at 0.977 (confidence interval, CI 0.957 to 0.990) as compared and validated with a reference clinical immunofluorescence assay, confirming an excellent correlation between both techniques. The multiplex biosensor system with on-demand panel composition can be used fully autonomously in clinical or mobile laboratory settings without the need for any additional medical equipment, with which could make it suitable for massive allergy screening campaigns to better define sensitization profiles.