An immunosensor based on magnetic relaxation switch and polystyrene microparticle-induced immune multivalency enrichment system for the detection of Pantoea stewartii subsp. Stewartii

• Published in: Biosensors & bioelectronics 2013-05, Vol.43, p.6-11
• Main Authors: Chen, Yi ping, Zou, Ming qiang, Wang, Da ning, Li, Yong liang, Xue, Qiang, Xie, Meng xia, Qi, Cai
• Format: Article
• Language: English
• Subjects: Bacterial Load - immunology; Bacterial Load - instrumentation; Biological and medical sciences; Biosensing Techniques - instrumentation; Biosensors; Biotechnology; Equipment Design; Equipment Failure Analysis; Fundamental and applied biological sciences. Psychology; Immune multivalency enhancement system; Immunoassay - instrumentation; Immunomagnetic Separation - instrumentation; Magnetic iron oxide nanoparticles (MION); Magnetic relaxation switch (MRS); Methods. Procedures. Technologies; Microspheres; Pantoea - immunology; Pantoea - isolation & purification; Pantoea stewartii subsp. Stewartii (Pss); Polystyrenes - chemistry; Various methods and equipments
• ISSN: 0956-5663; 1873-4235
• DOI: 10.1016/j.bios.2012.11.022

A rapid, sensitive, and simple immunosensor has been developed for the detection of Pantoea stewartii subsp. Stewartii (Pss). This immunosensor combines magnetic relaxation switch (MRS) assay with polystyrene microparticle-induced immune multivalency enrichment system. Comparing to conventional enzyme-linked immunosorbent assay (ELISA), the immunosensor developed in this study provides higher sensitivity and requires less analysis time. The detection limit of Pss obtained by immunosensor was determined to be 103cfu/mL, 50 times lower than that by ELISA (5×104cfu/mL), while the analysis time required by immunosensor is 30min much shorter than that by ELISA. The average recoveries studied with Pss at various spiking levels ranged from 85.5% to 93.4% with a relative standard deviation (RSD) below 6.0%. No cross-reaction with the other five strains was found, demonstrating a good specificity of Pss detection. The results showed that the MRS immunosensor combined with PS-induced immune multivalency enhancement system is a promising platform for the determination of large biological molecules due to its high sensitivity, specificity, homogeneity, and speed. ► An immunosensor combines magnetic relaxation switch and immune multivalency enrichment system. ► The LOD of this MRS immunosensor was determined to be 50 times lower than that by ELISA. ► The analysis time of MRS immunosensor (30min) was much shorter compared with that of ELISA.