Copper nanoclusters (Cu NCs) with a core size smaller than 2 nm exhibit fascinating physical and chemical properties, bridging between nanoparticles and atomic/molecular structures. In particular, the unique fluorescence (FL) characteristics of Cu NCs have attracted increasingly attention in the past decade. Compared with gold or silver NCs, Cu is a relatively cheap, abundant and readily available element, which makes Cu NCs more attractive to the development of sensors. However, Cu NCs still face serious issues, such as low quantum yield and easy to oxidation. This review discusses the latest developments in Cu NCs, with particular emphasis on their synthesis, optical properties, and applications in monitoring water quality. Pivotal factors that control the stability and FL properties of Cu NCs are emphasized. Examples of Cu NCs for monitoring of pH values and sensing of various analytes such as Hg²⁺, NO₂⁻, S²⁻, I⁻, and 2,4,6-trinitrotoluene are provided to show their sensing mechanisms, advantages, and disadvantages. Possible strategies for overcoming the low quantum yields and small scales of preparation of Cu NCs are suggested. To make Cu NCs more popular for sensing, we suggest that Cu NCs shall be integrated with portable microsystems such as array and microfluidic devices.

核心尺寸小于2 nm的铜纳米簇（Cu NCs）表现出令人着迷的物理和化学特性，桥接在纳米颗粒和原子/分子结构之间。特别地，在过去的十年中，Cu NCs的独特荧光（FL）特性引起了越来越多的关注。与金或银NC相比，Cu是一种相对便宜，丰富且易于获得的元素，这使Cu NC对传感器的发展更具吸引力。然而，Cu NCs仍然面临严重的问题，例如低量子产率和易于氧化。这篇评论讨论了铜纳米管的最新发展，特别是它们的合成，光学性质以及在监测水质中的应用。强调控制Cu NCs稳定性和FL特性的关键因素。²⁺，NO ₂ ^-，S ^2-，我^- ，和2,4,6-三硝基甲苯被提供以显示它们的感测机制，优点和缺点。建议了可能的策略，以克服低量子产率和制备小规模的铜NCs。为了使Cu NCs在感应中更加流行，我们建议将Cu NCs与便携式微系统（如阵列和微流体设备）集成在一起。