The robust point-of-care platform for sensitive, multiplexed,
and
affordable detection of allergen-specific IgE (sIgE) is an urgent
demand in component-resolved diagnostics. Here, we developed a microfluidic
immunosensing platform based on a rolling circle amplification-assisted
DNA dendrimer probe for sensitive detection of multiple sIgEs. The
versatile multichannel microfluidic whole blood analytical device
integrates cell filtration, recombinant antigen-modified magnetic
enrichment, and DNA dendrimer probe-amplified signal transduction
for portable on-chip analysis. Three sIgEs against common oyster allergens
were simultaneously detected in blood samples by simple smartphone-based
imaging without any pretreatment. The quantitative detection of multiple
allergen-specific antibodies on the platform was achieved with limits
of detection of less than 50 pg/mL, exhibiting superior sensitivity
compared to most point-of-care testing. The detection results of 55
serum samples and 4 whole blood samples were 100% consistent with
the ELISA results, confirming the accuracy and stability of our platform.
Additionally, the reversible combination of hexahistidine6-tag and Ni-IMAC magbead was elegantly utilized on the immunosensing
platform for desired reversibility. With the advantages of general
applicability, high sensitivity, and reversibility, the DNA dendrimer-based
microfluidic immunosensing platform provides great potential for the
portable detection of immune proteins as a point-of-care platform
in disease diagnostics and biological analysis.