Fluorescent nanomaterials have important applications in environmental monitoring and biomedicine and imaging. However, their preparation often is cumbersome, expensive, and extremely small-scale, requires harsh conditions, which limit their wide and practical applications. Herein, by directly reusing waste fish scales with intrinsic fluorescent property as precursors, we developed a facile, large-scale, inexpensive, and green method for extraction of fluorescent carbon nanoparticles for sensing of Fe³⁺. Our preparation approach only requires soaking fish scales in water without harsh conditions and complicated operations, only based on physical exfoliation, not limited by containers. Fish-scale-derived fluorescent carbon nanoparticles with bright blue fluorescence and a quantum yield of 15.6% are irregular spheres with a diameter of more than 60 nm, contained smaller nanodots with a diameter of about 4.2 nm, which has obvious lattice fringes of 0.23 nm. Elemental and functional group analysis confirmed that fluorescent carbon nanoparticles were mainly composed of C, O, and N, had hydroxyl, amine, and carbonyl groups, and similar in composition to collagens and hydroxyapatites. Fluorescent carbon nanoparticles can be used for fluorescent quenching-based detection of Fe³⁺ with a linear range of 0–6.25 μM and detection limit of 0.144 μM, and have good recoveries for Fe³⁺ in actual water samples and human serum with low relative standard deviations. This study not only adds a new dimension to provide a large-scale, simple, green, and promising method for reuse of waste fish scales, but also offers a new idea for the large-scale preparation and application of fluorescent carbon nanomaterials.

荧光纳米材料在环境监测以及生物医学和成像中具有重要的应用。然而，它们的制备通常麻烦，昂贵并且规模极小，需要苛刻的条件，这限制了它们的广泛和实际应用。本文中，通过直接重复使用具有固有荧光特性的废鱼鳞作为前体，我们开发了一种简便，大规模，廉价且绿色的方法，用于提取用于检测Fe ³⁺的荧光碳纳米颗粒。。我们的制备方法仅需将鱼鳞浸泡在水中，而无需进行苛刻的条件和复杂的操作，仅基于物理剥落，而不受容器的限制。鱼鳞来源的荧光碳纳米粒子，具有明亮的蓝色荧光，量子产率为15.6％，是直径大于60 nm的不规则球体，包含直径约4.2 nm的较小纳米点，具有明显的0.23 nm晶格条纹。元素和官能团分析证实，荧光碳纳米颗粒主要由C，O和N组成，具有羟基，胺基和羰基，其组成与胶原蛋白和羟基磷灰石相似。荧光碳纳米颗粒可用于基于荧光猝灭的Fe ³⁺检测线性范围为0–6.25μM，检出限为0.144μM，在实际水样和人血清中的Fe ³⁺回收率高，相对标准偏差低。这项研究不仅为新的规模提供了一种大规模，简单，绿色，有前途的废鱼鳞再利用方法，而且为荧光碳纳米材料的大规模制备和应用提供了新思路。