Abstract In the present study, a multicolor conversion strategy based on gold nanorods (AuNRs) assisted silver mirror reaction is developed for visual quantification of formaldehyde (HCHO). The method involves the silver deposition on the surface of AuNRs via the reduction reaction of Tollens' reagent in the presence of HCHO. The peak shifts of the longitudinal localized surface plasmon resonance (LSPR) and color variations of AuNRs solution are sensitive to the thickness of silver layer deposited on the surface of AuNRs. Under the optimized conditions, there is a good linear relationship between the peak shift and the concentration of HCHO (for both liquid sample and gas sample) in a wide range of concentration, thus an AuNRs based colorimetric assay for quantitative analysis of HCHO is established. Moreover, a series of consecutive color changes (from mauve to dusty blue, nattier blue, blue, mazarine blue, dark green, clay bank and finally orange red) responding to the presence and amount of HCHO enables visual semi-quantitative determination of HCHO within 15 min, and the clearly discernible dosage scale is as low as 0.10 μM. This assay exhibits desirable selectivity for HCHO over several common interfering organic molecular species and potential gas interferents, which has been successfully applied to measure the concentration of HCHO indoor.

中文翻译：

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金纳米棒辅助银镜反应连续变色基于现场视觉半定量室内甲醛

摘要 在本研究中，开发了一种基于金纳米棒 (AuNRs) 辅助银镜反应的多色转换策略，用于甲醛 (HCHO) 的视觉量化。该方法涉及在 HCHO 存在下通过 Tollens 试剂的还原反应在 AuNRs 表面沉积银。纵向局域表面等离子体共振 (LSPR) 的峰移和 AuNRs 溶液的颜色变化对沉积在 AuNRs 表面的银层厚度敏感。在优化的条件下，峰位移与 HCHO 浓度（液体样品和气体样品）在较宽的浓度范围内具有良好的线性关系，从而建立了基于 AuNRs 的 HCHO 定量分析比色法。而且，响应 HCHO 的存在和数量的一系列连续颜色变化（从淡紫色到灰蓝色、nattier 蓝、蓝色、紫红色、深绿色、粘土库和最后的橙红色）能够在 15 分钟内对 HCHO 进行目视半定量测定，并且清晰可辨的剂量范围低至 0.10 μM。该测定对 HCHO 对几种常见的干扰有机分子种类和潜在的气体干扰物表现出理想的选择性，已成功应用于测量室内 HCHO 的浓度。