Rapid and sensitive detection of Staphylococcus aureus by using a long-period fiber grating immunosensor coated with egg yolk antibody

• Published in: Biosensors & bioelectronics Vol. 199; p. 113860
• Main Authors: Gan, Wenbo, Xu, Zhenli, Li, Yaowei, Bi, Wenchao, Chu, Luoyao, Qi, Qianyu, Yang, Yitao, Zhang, Peiqing, Gan, Ning, Dai, Shixun, Xu, Tiefeng
• Format: Journal Article
• Language: English
• Published: England Elsevier B.V 01-03-2022
• Subjects: Antibodies, Bacterial; Biosensing Techniques; Egg Yolk; Immunoassay; Immunosensor; Long-period fiber grating; Staphylococcus aureus; Yolk antibody; Yolk antibody; Long-period fiber grating; Immunosensor; Staphylococcus aureus
• ISSN: 0956-5663; 1873-4235
• DOI: 10.1016/j.bios.2021.113860

The rapid and reliable detection of bacteria plays an important role in clinical and veterinary practice. A stable, label free, compact, and sensitive long-period fiber grating (LPFG) sensor based on egg yolk antibody (IgY) was proposed for the detection of Staphylococcus aureus (S. aureus). LPFG was fabricated with laser writing technology, and specific IgY was further immobilized on the grating region and then combined with the corresponding bacteria. S. aureus was detected by tracking the change of resonance wavelength in the LPFG transmission spectrum caused by bacteria–antibody interaction induced by the increase of biological cover thickness and density after the immune reaction. The testing results showed that the proposed sensor was selective and sensitive to S. aureus measurement, and the detection limit is approximately 33 CFU/ml. The proposed antibody immobilization method is very simple, and the optical fiber can be manufactured in batch to reduce the cost. The detection time of the sensor is around 20 min, which is fast and suitable for detection. The assay was successfully applied for the quantitative analysis of S. aureus in natural waters and met the needs of on-site screening trace pathogenic bacteria in food safety control.
•An immunosensor based on long period fiber grating is fabricated with selective detection of Staphylococcus aureus (S.A).•The yolk antibody (IgY) was used to detect bacteria specifically.•Fast response with a detection time of 20 min and detection limits of 33 CFU/ml S.A in water was achieved.•The immunosensor shows good repeatability and can be reused by surface-regeneration.