Saber Reza, Mutlu Selma, Pişkin Erhan
Department of Chemical Engineering and Bioengineering Division, Hacettepe University, 06532 Beytepe, Ankara, Turkey.
Biosens Bioelectron. 2002 Sep;17(9):727-34. doi: 10.1016/s0956-5663(02)00058-1.
The aim of this study is to develop an immunoaffinity sensor based on piezoelectric crystals for human serum albumin (HSA) detection in aqueous media. Quartz crystals were treated with ethylene diamine (EDA) plasma in a glow-discharge apparatus in order to substitute amino groups on their surfaces. Then anti-HSA antibodies were immobilized via these amino groups by using glutaraldehyde (GA) as cross-linker. Immobilization of the antibody on the quartz crystal was examined for different pH, antibody concentration and treatment time. The optimum conditions for anti-HSA immobilization were evaluated by the measurements of the activity of the surface against HSA. The optimum values of pH, antibody concentration and treatment time were found 6.2, 0.15 mg/ml and 2 h, respectively. For detection of HSA into the solution, two methods were used. In the first (dip and dry) method, the frequency shifts were measured in air after the 1 h interaction of the anti-HSA immobilized crystals with HSA solution. In the other (direct) method, the frequency shifts were followed continuously for 60 min. while the probe was immersed in the HSA solution. An increase for the frequency shifts was observed with increasing of HSA concentration of 16-128 microg/ml. Both the immobilization and antibody-interaction conditions were found important on the extend of these specific interaction. The relations between the HSA concentrations and frequency shifts were exponential in both methods.
本研究的目的是开发一种基于压电晶体的免疫亲和传感器，用于检测水性介质中的人血清白蛋白（HSA）。在辉光放电装置中用乙二胺（EDA）等离子体处理石英晶体，以在其表面取代氨基。然后以戊二醛（GA）作为交联剂，通过这些氨基固定抗HSA抗体。针对不同的pH值、抗体浓度和处理时间，研究了抗体在石英晶体上的固定情况。通过测量表面对HSA的活性来评估抗HSA固定的最佳条件。发现pH值、抗体浓度和处理时间的最佳值分别为6.2、0.15 mg/ml和2小时。为了检测溶液中的HSA，使用了两种方法。在第一种（浸入和干燥）方法中，将固定有抗HSA的晶体与HSA溶液相互作用1小时后，在空气中测量频率变化。在另一种（直接）方法中，将探头浸入HSA溶液中时，连续跟踪频率变化60分钟。随着HSA浓度在16 - 128μg/ml范围内增加，观察到频率变化增加。发现固定条件和抗体相互作用条件对于这些特异性相互作用的程度都很重要。在两种方法中，HSA浓度与频率变化之间的关系都是指数关系。
