The current method for rapid and ultrasensitive detection of multiple heavy metals in environmental water still face challenge. Herein, the porous Co₃O₄ nanodisks with robust peroxidase-mimicking activity were prepared, and its catalytic activity can be significantly inhibited by the heavy metals like Cd(II), Hg(II), Pb(II) and As, which makes us to establish an ultrasensitive and rapid colorimetric sensor for the detection of multiple heavy metals. Further investigation reveals the anticompetitive inhibition effect of heavy metals on peroxidase-mimicking activity. The colorimetric sensor displays excellent sensitivity and selectivity, and the limits of detection (LOD) for Cd(II), Hg(II), Pb(II) and As are 0.085 μg·L⁻¹, 0.19 μg·L⁻¹, 0.2 μg·L⁻¹ and 0.156 μg·L⁻¹, respectively. Notably, the absorbance variation will be greater than 0.5 as the concentration of heavy metals exceeds 5 μg·L⁻¹, which can be clearly discriminated by the naked eyes. Moreover, the average recovery range of heavy metals in actual water samples is from 86.9% to 98.3%. The above results indicate that the proposed sensor exhibits excellent practical applicability for the rapid and ultrasensitive detection of multiple harmful heavy metals in several environmental water samples, which has potential bright application in protecting the environment and human health.

目前快速、超灵敏地检测环境水中多种重金属的方法仍面临挑战。在此，制备了具有强过氧化物酶模拟活性的多孔 Co ₃ O ₄纳米盘，其催化活性可被重金属如 Cd(II)、Hg(II)、Pb(II) 和 As 显着抑制，这使得我们建立了一种用于检测多种重金属的超灵敏快速比色传感器。进一步的研究揭示了重金属对过氧化物酶模拟活性的反竞争抑制作用。比色传感器具有出色的灵敏度和选择性，Cd(II)、Hg(II)、Pb(II) 和 As 的检测限 (LOD) 分别为 0.085 μg·L ^-1、0.19 μg·L ^-1，分别为0.2 μg·L ^-1和0.156 μg·L ^-1。值得注意的是，当重金属浓度超过5 μg·L ^-1时，吸光度变化将大于0.5，肉眼可以清楚地区分。此外，实际水样中重金属的平均回收率范围为 86.9% 至 98.3%。上述结果表明，所提出的传感器在快速、超灵敏地检测多种环境水样中的多种有害重金属方面表现出优异的实际适用性，在保护环境和人类健康方面具有广阔的应用前景。