Modification of the SERS spectrum of cyanide traces due to complex formation between cyanide and silver

Abstract

It is well known that cyanide is an extremely toxic lethal poison with human death within minutes after exposure to only 300 ppm cyanide. On the other hand, cyanide is released into the environment (mainly through waste water) every day from various human activities. Therefore, rapid, sensitive and cost-effective cyanide trace detection is an urgent need. Surface-enhanced Raman scattering (SERS) is a method that meets these requirements. It should be noted, however, that in this technique SERS substrates, which are usually made of gold or silver, will be leached with aqueous cyanide by the formation of complexes between gold or silver with cyanide. This will cause the SERS spectrum of cyanide to be modified. When determining cyanide concentrations by SERS analysis, this spectral modification should be taken into account. This report presents the SERS spectral modification of aqueous cyanide traces (in ppm and lower concentration range) when the SERS substrates used are flower-like silver micro-structures.

Fabrication of Silver Nanostructures in the Form of Particles, Dendrites and Flowers on Silicon for Use in SERS Substrates

“…Furthermore, nano-flower structures usually appear only when in the electrolyte there is an additional morphological directing agent like polyvinylpyrrolidone (PVP), cetyltrimethylammonium bromide (CTAB) and the like. In this report, AgNFs prepared on Si by the chemical deposition in an aqueous solution containing 4.8 M HF, 1 mM AgNO 3 , 10 mM AsA and 5 mM PVP at room temperature for 10 minutes [19] are shown in Fig. 3c and 3d.…”

“…The fabrication of arrays of silver nanoparticles, nanodendrites or nanoflowers on silicon surface has been described in detail in our works [11,15,18,19]. In brief, to produce an array of silver nanoparticles (AgNPs) on silicon, both chemical and electrochemical deposition can be used.…”

“…The Si sample was immersed in an aqueous solution containing 4.8 M HF, 1 mM AgNO 3 , 10 mM ascorbic acid (AsA) and 5 mM polyvinyl pyrrolidone (PVP) for 10 min. After silver deposition, the samples were all washed with deionized water, then left to dry naturally in the air [19].…”

Carbon-Nitrogen Bond Formation on Cu Electrodes During Co2 Reduction in No3- Solution

“…3a) which matches the peak observed in our experiments. It was proven that SERS can be successfully used for detection of trace amounts of cyanides as demonstrated for Au in the gas phase 42 as well as in solution on Ag 51 and Cu surfaces, where Cu(I) surfaces can be very effective in detection by forming CuCN 52 . The position of the peak is similar to the C ≡ N stretching position (frequency) of solid CuCN 40 and surprisingly, it changes depending on CN − concentration (Fig.…”

Progress in Fluorescent Probes for Cu2+ and Anions, Neutral Molecules Sequential Recognition

“…世界健 康组织对饮用水中 CN -的含量要求最高不能超过 1.9 μmol•L -1 [53] , 这主要是由于过量的 CN -会同血红素结 合, 抑制生命体细胞的呼吸. 检测 CN -的方法较多, 包 括氢键的相互作用 [54] 、形成氰配合物 [55] 、通过亲核作用 于活化后的羰基或碳-碳双键 [56] 以及"替换"法. 目前, 利用含有 Cu 2＋ 的配合物作为传感器, 通过"替换法"可 高效地实现对 CN -快速专一的连续识别.…”