Selenium, a metalloid, commonly known for its essentiality has emerged out as a water pollutant of concern for environmentalist due to its presence in natural water resources above the permissible limit. The high level of selenium in the environment poses severe health and ecosystem threats, therefore, its monitoring in water is of paramount concern. The present contribution summarizes and critically analyzes the field promising techniques, in particular, voltammetry and optical approach, for selenium quantification in water. The role of sensor material (organic fluorophores, colorimetric dyes and quantum dots), electrode surface modifiers (Hg, Bi, polymers, nano materials, etc.), chelators, etc., to overcome various challenges and achieve better sensor performance in terms of detection limit, range, reproducibility, stability, selectivity, sensitivity, and so forth are critically discussed. To end with, the possible future developments are discussed towards the realization of a cost-effective & field deployable monitoring device for on-site selenium analysis.

中文翻译：

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伏安和光学技术测定水中无机硒的系统综述和荟萃分析

硒是一种准金属，由于其必不可少，因此已成为环保主义者关注的水污染物，因为它在自然水资源中的含量超过了允许的限度。环境中的硒含量高，对健康和生态系统构成严重威胁，因此，水中的硒监测至关重要。本文稿总结并批判性地分析了用于水中硒定量分析的有前途的技术，特别是伏安法和光学方法。传感器材料（有机荧光团，比色染料和量子点），电极表面改性剂（汞，铋，聚合物，纳米材料等），螯合剂等的作用是克服各种挑战并在以下方面实现更好的传感器性能：检测限，范围，重现性，稳定性，选择性，敏感度等问题进行了严格的讨论。最后，讨论了可能实现的未来发展，以实现用于现场硒分析的经济高效且可现场部署的监测设备。