A New Concept for Efficient Sensitivity Amplification of a QCM Based Immunosensor for TNF-alpha by Using Modified Magnetic Particles under Applied Magnetic Field

作者：Bahk Yeon Kyoung; Kim Hyung Hoon; Park Deog Su; Chang Seung Cheol^*; Go Jeung Sang

来源：BULLETIN OF THE KOREAN CHEMICAL SOCIETY, 2011, 32(12): 4215-4220.

DOI：10.5012/bkcs.2011.32.12.4215

• Biosensor
• Immunosensor
• Quartz crystal microbalance
• Magnetic particles
• TNF-alpha

This study introduces a new concept for a simple, efficient and cheap sensitivity amplification of a Quartz Crystal Microbalance (QCM) based immunosensor system for the detection of tumor necrosis factor-alpha (TNF-alpha, TNF) by using an in-built magnetic system. The frequency shift due to the applied magnetic field was successfully observed on magnetic particles labeled detection antibodies, anti-human TNF-alpha, which were bound to the immunologically captured TNF-alpha on the gold coated quartz crystals. In the present system, the magnitude of frequency shift depends on both the strength of magnetic field and the amount of target antigen applied. Significant signal amplification was observed when the additional built-in residual stress generated by the modified magnetic particles under the magnetic field applied. Used in conjunction with a sandwich type non-competitive immunoassay format, the lower detection limit was calculated to be 25 ngmL(-1) and showed good linearity up to TNF-alpha concentrations as high as 2.0 mu gmL(-1). The sensitivity, most importantly, was improved up to 4.3 times compared with the same QCM system which was used only an antigen-antibody binding without additional magnetic amplification.

• 出版日期2011-12-20