CESAM - Centre for Environmental and Marine Studies, Department of Biology, University of Aveiro, 3810-193, Aveiro, Portugal.
Department of Biology, University of Aveiro, 3810-193, Aveiro, Portugal.
Environ Pollut. 2022 Jun 1;302:118973. doi: 10.1016/j.envpol.2022.118973. Epub 2022 Feb 17.
Corrosion is an environmental and economic global problem. "Smart" or stimuli-responsive colorimetric nanosensors for maritime coatings have been proposed as an asset to overcome the limitations of the current monitoring techniques by changing color in the presence of triggers associated with the early stages of corrosion. Layered double hydroxides (Zn-Al LDH; Mg-Al LDH) and silica mesoporous nanocapsules (SiNC) were used as precursor nanocarriers of active compounds: hexacyanoferrate ions ([Fe(CN)]) and phenolphthalein (PhPh), respectively. Additionally, the safer-by-design principles were employed to optimize the nanosensors in an eco-friendly perspective (e.g., regular vs. warm-washed SiNC-PhPh; immobilization using different carriers: Zn-Al LDH-[Fe(CN)] vs. Mg-Al LDH-[Fe(CN)]). Therefore, the present study aims to assess the environmental behavior in saltwater and the toxic effects of the nanosensors, their nanocarriers, and the active compounds on the marine microalgae Tetraselmis chuii and the crustacean Artemia salina. Briefly, tested compounds exhibited no acute toxic effects towards A. salina (NOEC = 100 mg/L), apart from SiNC-PhPh (LC = 2.96 mg/L) while tested active compounds and nanosensors caused significant growth inhibition on T. chuii (lowest IC = 0.40 mg/L for SiNC-PhPh). The effects of [Fe(CN)] were similar regardless of the nanocarrier choice. Regarding SiNC-PhPh, its toxicity can be decreased at least twice by simply reinforcing the nanocapsules washing, which contributes to the removal (at least partially) of the surfactants residues. Thus, implementing safe-by-design strategies in the early stages of research proved to be critical, although further progress is still needed towards the development of truly eco-friendly nanosensors.
腐蚀是一个全球性的环境和经济问题。“智能”或刺激响应比色纳米传感器已被提议用于海洋涂料，以通过在与腐蚀早期阶段相关的触发存在的情况下改变颜色来克服当前监测技术的局限性。层状双氢氧化物（Zn-Al LDH；Mg-Al LDH）和硅介孔纳米胶囊（SiNC）分别用作活性化合物的前体纳米载体：六氰合铁（Fe(CN)）和酚酞（PhPh）离子。此外，还采用了更安全的设计原则，从环保的角度优化纳米传感器（例如，常规与温暖洗涤的 SiNC-PhPh；使用不同载体的固定化：Zn-Al LDH-[Fe(CN)]与 Mg-Al LDH-[Fe(CN)]）。因此，本研究旨在评估纳米传感器及其纳米载体和活性化合物在盐水中的环境行为以及对海洋微藻四尾栅藻和甲壳类动物卤虫的毒性影响。简而言之，测试化合物对卤虫（NOEC = 100 mg/L）没有急性毒性作用，除了 SiNC-PhPh（LC = 2.96 mg/L）之外，而测试的活性化合物和纳米传感器对四尾栅藻的生长抑制作用明显（SiNC-PhPh 的最低 IC = 0.40 mg/L）。无论纳米载体的选择如何，[Fe(CN)]的作用都相似。对于 SiNC-PhPh，通过简单加强纳米胶囊洗涤，可以至少将其毒性降低两倍，这有助于去除（至少部分去除）表面活性剂残留。因此，在研究的早期阶段实施安全设计策略被证明是至关重要的，尽管在开发真正环保的纳米传感器方面仍需要进一步的进展。
