Carboxymethyl chitosan assembled piezoelectric biosensor for rapid and label-free quantification of immunoglobulin Y.

Immunoglobulin Y (IgY) proves advantageous to IgG in prophylaxis and diagnosis. Quantification of IgY is therefore becoming a topic of interest. Here, we demonstrate a piezoelectric biosensor with carboxymethyl chitosan (CMCS) as the immobilization matrix. Gelation and hydrophilic nature of CMCS are favored to form a crosslinked matrix for antibody immobilization, and a comparison was made between carboxymethyl cellulose (CMC) and CMCS to investigate the benefits of such substitution. Calibration from 500 ng/mL to 200 μg/mL was established in buffer with the detection limit (LOD) down to 270 ng/mL, confirming its feasibility. As-prepared biosensor effectively prevents non-specific binding of bovine serum albumin (BSA) and lysozyme. Each real-time assay took 15 min including sensor regeneration, which can be further reduced to 4 min for signal readout only, ready for both repeated measurements after regeneration and disposable devices. Thus, as-prepared biosensor offers a rapid, label-free and cost-effective approach for IgY quantification.