Quantifying the relative bioavailability of particles versus ions is a key step toward understanding the mechanisms of bioaccumulation and toxicity of silver nanoparticles (AgNPs). Here we investigated AgNP uptake kinetics by wheat Triticum aestivum L. at different ages (i.e. 15- and 30-day after germination) in hydroponics. The concentration-dependent accumulation of AgNPs under the experimental conditions, in which AgNP dissolution in bulk suspension and at the biological interface was ruled out, confirmed the direct uptake of particles. This was further validated by the detection of Ag-containing particles within plants by single particle inductively coupled plasma mass spectrometry. Plants differentiated particles and dissolved ions, with uptake rate constants of particles and dissolved ions 4.3 ± 0.6 to 5.2 ± 0.6 and 288.6 ± 13.4 to 450.6 ± 63.4 L kg⁻¹ h⁻¹, respectively. Plant age appeared to have a negligible influence on uptake rate constant ratio of particles to ions. As a result, the relative contribution of particulate uptake to overall AgNP accumulation varied as a function of AgNP dissolution in nature. Particulate uptake was dominant when the dissolution was less than 1.2%. These findings help clearing up the inconsistency of uptake mechanisms of AgNPs in literature and could be used to predict their environmental impact and significance.

量化粒子与离子的相对生物利用度是理解银纳米粒子（AgNPs）的生物累积和毒性机制的关键一步。在这里，我们研究了小麦小麦对AgNP的吸收动力学。L.在不同年龄（即发芽后15天和30天）的水培法中。在实验条件下排除了AgNP的浓度依赖性积累，其中排除了AgNP在整体悬浮液中和在生物界面处的溶解，证实了颗粒的直接摄取。通过单粒子感应耦合等离子体质谱法检测植物中的含银粒子进一步证实了这一点。种植分化的颗粒和溶解的离子，颗粒和溶解的离子的吸收速率常数为4.3±0.6至5.2±0.6和288.6±13.4至450.6±63.4 L kg ^-1 h ^-1， 分别。植物年龄似乎对颗粒与离子的吸收速率恒定比的影响可忽略不计。结果，颗粒吸收对总体AgNP积累的相对贡献随自然界中AgNP溶解的函数而变化。当溶出度小于1.2％时，颗粒吸收占主导。这些发现有助于清除文献中AgNPs摄取机制的不一致，并可用于预测其对环境的影响和意义。