草鱼鳞胶原蛋白纳米银溶胶的制备及其对水中Cr(Ⅲ)的检测

Preparation of Nano-Ag Sol of Grass Carp Scale Collagen and Its Detection of Cr(Ⅲ) in Water

以草鱼鳞胶原蛋白为稳定剂,AgNO3为银源,茶多酚(TP)为还原剂,采用化学还原法快速合成了草鱼鳞胶原蛋白纳米银(Col-nAg)溶胶。考察了AgNO3浓度、pH值及TP浓度对Col-nAg溶胶制备的影响。得到Col-nAg溶胶的最优制备条件为0.02 mol/L AgNO3,pH 7.0和2 mol/L TP,所得纳米银平均粒径为4.45 nm,且可在4℃下保存60 d无明显变化。将Col-nAg溶胶用于Cr3+检测,纳米银颗粒与Cr3+之间发生非交联团聚,溶胶颜色由黄色变为褐色,纳米银粒径变大,检测范围为0~10μg/mL,检出限为0.5μg/mL。最优检测条件为pH 7.0,25℃下反应5 min。该反应对Cr3+具有高选择性。

In the current study,the nano-Ag sol of grass carp scale collagen(Col-nAg sol) was prepared by chemical reduction method,using silver nitrate solution with tea polyphenols(TP) as reducing agent and while collagen of grass carp scale as stabilizer.Effects of AgNO3 concentration,TP concentration and pH value on the preparation of Col-nAg sol were studied.Results showed that the optimal preparation conditions for Col-nAg sol were as follows:0.02 mol/L for AgNO3,pH 7.0 and 2 mol/L for TP.The average particle size for nano-Ag was 4.45 nm,which could be preserved at 4 ℃ for 60 days without obvious change.The Col-nAg sol was applied in the detection of Cr3+.Non-crosslinking agglomeration occurred between the nano-Ag particles and Cr3+,which caused a dramatic color change of Col-nAg sol from yellow to brown and a larger particle size of nano silver.The method was highly selective and sensitive in the detection of Cr3+ with a detection range of 0-10 μg/mL and a detection limit of 0.5 μg/mL.Parameters such as detection time,temperature and pH were optimized to obtain precise detection limit.