Das R Dev, RoyChaudhuri C, Maji S, Das S, Saha H
Department of Electronics and Telecommunication Engineering, Bengal Engineering and Science University Shibpur, West Bengal, India.
Biosens Bioelectron. 2009 Jul 15;24(11):3215-22. doi: 10.1016/j.bios.2009.04.014. Epub 2009 Apr 17.
A thermally oxidized macroporous silicon substrate with simple electrode structure without interdigitated electrode configuration has been reported for the detection of Salmonella typhimurium pathogens by electrical impedance measurement using antibody-antigen binding method. Macroporous silicon which has been fabricated by anodizing silicon in HF and DMF solution is a regular network of pores of 1-2 microm diameters. This has been thermally oxidized to yield the surface hydrophilic for antibody immobilization as well as provide suitable electrical insulation of the metal contacts from the underlying conducting silicon substrate. The macroporous silicon surface has been immobilized by Salmonella specific antibody and has been tested with different concentration of S. typhimurium pathogens in phosphate buffer solution (PBS). It has been found that such macroporous silicon substrates is capable of detecting down to 10(3)CFU/ml in pure culture using a 3 mm x 1 mm electrode structure with a wide spacing of 1mm. The selectivity of the macroporous silicon substrates with reference to S. typhimurium has been tested to be satisfactory by carrying out controlled experiments with Escherichia coli O157:H7.
据报道，一种具有简单电极结构且无叉指电极配置的热氧化大孔硅衬底，可通过使用抗体 - 抗原结合方法的电阻抗测量来检测鼠伤寒沙门氏菌病原体。通过在氢氟酸和二甲基甲酰胺溶液中对硅进行阳极氧化制备的大孔硅是一种直径为1 - 2微米的规则孔网络。对其进行热氧化，以使表面具有亲水性用于固定抗体，并为金属触点与下面的导电硅衬底提供合适的电绝缘。大孔硅表面已固定有沙门氏菌特异性抗体，并在磷酸盐缓冲溶液（PBS）中用不同浓度的鼠伤寒沙门氏菌病原体进行了测试。已发现，使用具有1毫米宽间距的3毫米×1毫米电极结构，这种大孔硅衬底能够在纯培养物中检测低至10³CFU/ml的病原体。通过用大肠杆菌O157:H7进行对照实验，测试了大孔硅衬底对鼠伤寒沙门氏菌的选择性，结果令人满意。
