Shtenberg Giorgi, Massad-Ivanir Naama, Segal Ester
The Inter-Departmental Program of Biotechnology, Technion - Israel Institute of Technology, Haifa 32000, Israel.
Analyst. 2015 Jul 7;140(13):4507-14. doi: 10.1039/c5an00248f.
A generic biosensing platform, based on nanostructured porous Si (PSi), Fabry-Pérot thin films, for label-free monitoring of heavy metal ions in aqueous solutions by enzymatic activity inhibition, is described. First, we show a general detection assay by immobilizing horseradish peroxidase (HRP) within the oxidized PSi nanostructure and monitor its catalytic activity in real time by reflective interferometric Fourier transform spectroscopy. Optical studies reveal the high specificity and sensitivity of the HRP-immobilized PSi towards three metal ions (Ag(+) > Pb(2+) > Cu(2+)), with a detection limit range of 60-120 ppb. Next, we demonstrate the concept of specific detection of Cu(2+) ions (as a model heavy metal) by immobilizing Laccase, a multi-copper oxidase, within the oxidized PSi. The resulting biosensor allows for specific detection and quantification of copper ions in real water samples by monitoring the Laccase relative activity. The optical biosensing results are found to be in excellent agreement with those obtained by the gold standard analytical technique (ICP-AES) for all water samples. The main advantage of the presented biosensing concept is the ability to detect heavy metal ions at environmentally relevant concentrations using a simple and portable experimental setup, while the specific biosensor design can be tailored by varying the enzyme type.
本文描述了一种基于纳米结构多孔硅（PSi）、法布里-珀罗薄膜的通用生物传感平台，用于通过酶活性抑制对水溶液中的重金属离子进行无标记监测。首先，我们通过将辣根过氧化物酶（HRP）固定在氧化的PSi纳米结构中展示了一种通用检测方法，并通过反射干涉傅里叶变换光谱实时监测其催化活性。光学研究表明，固定有HRP的PSi对三种金属离子（Ag(+) > Pb(2+) > Cu(2+)）具有高特异性和灵敏度，检测限范围为60 - 120 ppb。接下来，我们通过将多铜氧化酶漆酶固定在氧化的PSi中，展示了对Cu(2+)离子（作为典型重金属）进行特异性检测的概念。所得生物传感器通过监测漆酶的相对活性，能够对实际水样中的铜离子进行特异性检测和定量。发现所有水样的光学生物传感结果与通过金标准分析技术（ICP - AES）获得的结果高度一致。所提出的生物传感概念的主要优点是能够使用简单便携的实验装置检测环境相关浓度的重金属离子，同时可以通过改变酶的类型来定制特定的生物传感器设计。
