Semicontinuous Measurement of Mite Allergen (Der f 2) Using a Surface Acoustic Wave Immunosensor under Moderate pH for Long Sensor Lifetime

Abstract

In this work, we developed a surface-acoustic-wave (SAW)-based immunosensor for the monitoring of house dust mite (HDM) allergen, Dermatophagoides farinae group 2 (Der f 2). The SAW immunosensor was fabricated by modifying the sensor surface with a self-assembled monolayer of ORLA85 protein and immobilized capture antibodies (cAb) for Der f 2. Because of the pH-insensitive property of ORLA85, the sensor surface could be used for successive measurement and regeneration of the sensor surface. In experiments, first, the conditions for cAb immobilization on the sensor surface were optimized, and then the sensor properties were investigated. These revealed the limit of detection of the SAW immunosensor for Der f 2 to be 6.3 ng/mL and hence, the sensor's high selectivity to Der f 2. Finally, the optimum pH for regeneration, at which the regeneration efficiency and sensor output were balanced, was investigated. It showed that the use of pH 4.0 HCl for regeneration allowed reproducible sensor outputs, and less damage to immobilized cAb; thus, longer sensor lifetime could be expected. The results allowed us to anticipate that the SAW immunosensor would be usable for sensitive, selective, and repeated measurement of Der f 2 with a longer lifetime, and it would be a promising sensor for HDM allergen monitoring.

Recent Advances in Monitoring, Sampling, and Sensing Techniques for Bioaerosols in the Atmosphere

“…The same research group also fabricated a SAW-based immunosensor for the detection of D. farinae group 2 allergens (Der f 2). 78 A sensor was fabricated by 79 This microfluidic immunosensor achieved an LOD of 1 and 10 pg/mL with a spectrometer and cell phone camera as an optical detector, respectively. The experiment comprised sampling over 30 s and microfluidic detection over 5 min.…”

“…This exhibited high reproducibility for certain targets with a few residual molecules after regeneration to facilitate the extended use of the sensor as well. The same research group also fabricated a SAW-based immunosensor for the detection of D. farinae group 2 allergens ( Der f 2 ) . A sensor was fabricated by modifying the probe surface with a self-assembled monolayer of ORLA85 protein and immobilized capture antibodies (cAb) for Der f 2 .…”

Reusable Surface Plasmon Resonance Immunosensor for Temporal Information of Protein Biomarkers

“…This result, showing that the strongest binding between protein G and IgG occurred under a slightly acidic condition, agrees with previous studies. (19,20,28) The dependence of the binding on the mIgG concentration was investigated, and it was found that more binding occurred with increasing concentration [see Fig. 3(c)].…”

“…Previously, we developed a surface-acoustic-wave-based reusable immunosensor for the semicontinuous measurement of mite allergens. (19)(20)(21) The sensor utilized a highly stable protein to anchor capture antibodies. This surface modification allowed repeated measurement of mite allergens with high reproducibility.…”

Application of Shear Horizontal Surface Acoustic Wave (SH-SAW) Immunosensor in Point-of-Care Diagnosis

“…Qorvo Biotechnologies has obtained an emergency use authorization (EUA) from the FDA for the rapid detection of the COVID-19 antigen by using BAW at the point of care [ 22 ]. On the other hand, SH-SAW sensors are popular in liquid phase applications [ 23 , 24 , 25 , 26 , 27 , 28 , 29 ]. In addition, a unique SH-SAW biosensor system has been commercialized for medical applications.…”