Department of Science Laboratory Technology, College of Science and Technology, Jigawa State Polytechnic, Dutse PMB 7040, Nigeria.
Department of Biochemistry, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, Serdang 43400 UPM, Selangor, Malaysia.
Int J Environ Res Public Health. 2020 Nov 19;17(22):8585. doi: 10.3390/ijerph17228585.
Potentially toxic metals pollution in the Straits of Malacca warrants the development of rapid, simple and sensitive assays. Enzyme-based assays are excellent preliminary screening tools with near real-time potential. The heavy-metal assay based on the protease ficin was optimized for mercury detection using response surface methodology. The inhibitive assay is based on ficin action on the substrate casein and residual casein is determined using the Coomassie dye-binding assay. Toxic metals strongly inhibit this hydrolysis. A central composite design (CCD) was utilized to optimize the detection of toxic metals. The results show a marked improvement for the concentration causing 50% inhibition (IC) for mercury, silver and copper. Compared to one-factor-at-a-time (OFAT) optimization, RSM gave an improvement of IC (mg/L) from 0.060 (95% CI, 0.030-0.080) to 0.017 (95% CI, 0.016-0.019), from 0.098 (95% CI, 0.077-0.127) to 0.028 (95% CI, 0.022-0.037) and from 0.040 (95% CI, 0.035-0.045) to 0.023 (95% CI, 0.020-0.027), for mercury, silver and copper, respectively. A near-real time monitoring of mercury concentration in the Straits of Malacca at one location in Port Klang was carried out over a 4 h interval for a total of 24 h and validated by instrumental analysis, with the result revealing an absence of mercury pollution in the sampling site.
马六甲海峡潜在有毒金属污染需要开发快速、简单和灵敏的分析方法。基于酶的分析方法是极好的初步筛选工具，具有接近实时的潜力。基于蛋白酶 ficin 的重金属分析方法使用响应面法进行了汞检测的优化。抑制分析基于 ficin 对底物酪蛋白的作用，使用考马斯亮蓝染料结合分析测定残留的酪蛋白。有毒金属强烈抑制这种水解。利用中心复合设计（CCD）对有毒金属的检测进行了优化。结果表明，汞、银和铜的 50%抑制浓度（IC）有明显改善。与单因素优化相比，RSM 使 IC（mg/L）得到改善，汞从 0.060（95%CI，0.030-0.080）提高到 0.017（95%CI，0.016-0.019），银从 0.098（95%CI，0.077-0.127）提高到 0.028（95%CI，0.022-0.037），铜从 0.040（95%CI，0.035-0.045）提高到 0.023（95%CI，0.020-0.027）。在 4 小时的间隔内，在巴生港的一个地点对马六甲海峡的汞浓度进行了近实时监测，共 24 小时，并通过仪器分析进行了验证，结果显示采样点没有汞污染。
