Detection of gliadin in foods using a quartz crystal microbalance biosensor that incorporates gold nanoparticles.
This work develops a label-free gliadin immunosensor that is based on changes in the frequency of a quartz crystal microbalance (QCM) chip. A higher sensitivity was obtained by applying 25 nm gold nanoparticles (AuNPs) to the surface of a bare QCM electrode. Subsequently, chicken anti-gliadin antibodies (IgY) were immobilized directly on the AuNP-modified surface by cross-linking amine groups in IgY with glutaraldehyde. Experimental results revealed that the change in frequency exhibited when 2 ppm gliadin was bound to the AuNP-modified electrode was 35 Hz (48%) greater than that of the bare gold electrode. The linear dynamic range in 60% ethanol was from 1 × 10(1) to 2 × 10(5) ppb gliadin, and the calculated limit of detection (LOD) was 8 ppb. The entire detection process was completed in 40 min and was highly repeatable. Additionally, the AuNP-modified QCM system generated results in the detection of gliadin in 10 commercial food products that were consistent with those obtained using an AOAC-approved gliadin kit. In conclusion, the QCM platform provides a potential alternative means of ensuring that people with wheat allergies and celiac patients have access to gliadin-free food.
Department of Food Science and Biotechnology, National Chung Hsing University, Taichung, Taiwan, Republic of China.
Pei-Tzu
PT
Chu
Chih-Sheng
CS
Lin
Wei-Jung
WJ
Chen
Chih-Feng
CF
Chen
Hsiao-Wei
HW
Wen
D015374:Biosensing Techniques; D004566:Electrodes; D005504:Food Analysis / Q000379:methods*; D005903:Gliadin / Q000032:analysis*; D006046:Gold; D053768:Metal Nanoparticles; D058525:Quartz Crystal Microbalance Techniques / Q000379:methods*
D006046:Gold; D005903:Gliadin