Surface plasmon resonance-based trace detection of small molecules by competitive and signal enhancement immunoreaction

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• 作者：Hidenobu Aizawa ; Mitsuhiro Tozuka ; Shigeru Kurosawa ; Koichi Kobayashi ; Subrayal M. Reddy ; Masahiro Higuchi
• 关键词：Surface plasmon resonance (SPR) ; SPR-immunosensor ; 2 ; 4-Dinitrophenol (DNP) ; DNP– ; protein conjugate ; Anti-DNP– ; protein monoclonal antibody ; Signal enhancement immunoreaction
• 刊名：Analytica Chimica Acta
• 出版年：2007
• 出版时间：22 May 2007
• 年：2007
• 卷：591
• 期：2
• 页码：191-194
• 全文大小：218 K

文摘

A surface plasmon resonance (SPR)-immunosensor for detection of the low molecular weight compound 2,4-dinitorophenol (DNP) at ultra-low concentration has been developed. The sensor strategy is based on a competitive immunoreaction between DNP and a DNP–protein conjugate, namely DNP–bovine serum albumin conjugate (DNP–BSA). Anti-DNP monoclonal antibody was immobilized on a gold thin-film coated SPR-sensor chip by means of a chemical coupling process. DNP–BSA, on contact with the anti-DNP antibody immobilized SPR-immunosensor chip causes an increase in the resonance angle of the sensor chip. The optimum concentration of immobilized antibody on the SPR-sensor chip is 100 μg mL⁻¹. The SPR-immunosensor response for free DNP determination using the competitive immunoreaction had a response time of ca. 15 min. Using this method, DNP could be determined in the concentration range 1 ppt to 1 ppb. The SPR signal for ppt levels of DNP was enhanced by a factor of three by subsequently treating immuno-bound DNP–BSA with a secondary anti-DNP antibody.