Nabok Alexei, Tsargorodskaya Anna, Holloway Alan, Starodub Nikolay F, Demchenko Anna
Sheffield Hallam University, Materials and Engineering Research Institute, City Campus, Pond Street, Sheffield S1 1WB, UK.
Langmuir. 2007 Jul 31;23(16):8485-90. doi: 10.1021/la700414z. Epub 2007 Jul 6.
The Binding of nonylphenol to respective antibodies immobilized on solid substrates was studied with the methods of total internal reflection ellipsometry (TIRE) and QCM (quartz crystal microbalance) impedance spectroscopy. The binding reaction was proved to be highly specific having an association constant of KA=1.6x10(6) mol(-1) L and resulted in an increase in both the adsorbed layer thickness of 23 nm and the added mass of 18.3 microg/cm2 at saturation. The obtained responses of both TIRE and QCM methods are substantially higher than anticipated for the immune binding of single molecules of nonylphenol. The mechanism of binding of large aggregates of nonylphenol was suggested instead. Modeling of the micelle of amphiphilic nonylphenol molecules in aqueous solutions yielded a micelle size of about 38 nm. The mechanism of binding of large molecular aggregates to respective antibodies can be extended to other hydrophobic low-molecular-weight toxins such as T-2 mycotoxin. The formation of large molecular aggregates of nonylphenol and T-2 mycotoxin molecules on the surface was proved by the AFM study.
采用全内反射椭圆偏振光谱法（TIRE）和石英晶体微天平（QCM）阻抗谱法研究了壬基酚与固定在固体基质上的相应抗体的结合。结果表明，该结合反应具有高度特异性，缔合常数KA = 1.6×10⁶ mol⁻¹ L，饱和时吸附层厚度增加23 nm，附加质量增加18.3 μg/cm²。TIRE和QCM方法获得的响应远高于壬基酚单分子免疫结合的预期值。相反，研究提出了壬基酚大聚集体的结合机制。对两亲性壬基酚分子在水溶液中的胶束进行建模，得到胶束尺寸约为38 nm。大分子聚集体与相应抗体的结合机制可扩展到其他疏水性低分子量毒素，如T-2霉菌毒素。原子力显微镜（AFM）研究证明了表面上壬基酚和T-2霉菌毒素分子形成了大分子聚集体。
