基于不同稳定剂纳米金冷融指示剂的制备及稳定性研究

为研究不同种类稳定剂对所制备纳米金溶胶性质的影响。本文以氯金酸为原料,选择柠檬酸三钠、海藻酸钠、壳聚糖3种不同性质的稳定剂分别制备纳米金溶胶,以冷冻前后溶胶颜色变化、溶胶等离子体吸收峰及其峰值的变化及颗粒间的聚集情况为考察指标,研究不同稳定剂所制备的纳米金冷融指示剂冷冻前后的稳定性。结果表明:以柠檬酸三钠为稳定剂所制备的纳米金溶胶颜色经一次冷冻就会由酒红色变为透明无色;以壳聚糖为稳定剂所制备的纳米金溶胶,其颗粒经冷冻后虽会聚集,但颜色不会发生明显变化。以上现象均不符合对指示剂的要求。以2.0%海藻酸钠与10 mL的1.0 mmol/L氯金酸溶液所制备的纳米金溶胶效果最为理想:溶胶经反复冷冻后,颜色由正红色变为紫色,且颜色随冷冻次数的增加而加深,其颗粒间会发生聚集,由单一分散变为聚集成团。以上现象均符合纳米金冷融指示剂的要求,因此以海藻酸钠为稳定剂所制备的纳米金溶胶是一种良好的纳米金冷融指示剂。

Preparation and Stability of Nano-gold Cold Melt Indicators Based on Different Stabilizers

In order to study the effect of different kinds of stabilizers on the properties of nano-gold sols prepared,nano-gold sols were prepared by using chloroauric acid as raw material and three kinds of stabilizers of trisodium citrate,sodium alginate and chitosan. The change of sol color before and after freezing,the change of sol plasma absorption peak and its peak value and the aggregation between particles were taken as indicators to study the stability of nano-gold cold-melt indicator prepared by different stabilizers before and after freezing. The results showed that:The color of the nano-gold sol prepared by using trisodium citrate as a stabilizer changed from wine red to transparent and colorless after one freezing. Nano-gold sol prepared by using chitosan as a stabilizer,the particles would accumulate after freezing,but the color would not change significantly. None of the above phenomena met the requirements for indicators. The nano-gold sol prepared by 2.0% sodium alginate and 10 mL of 1.0 mmol/L chloroauric acid solution was the most effective:After repeated freezing of the sol,the color changes from positive red to purple,and the color deepened with the increase of freezing time. The aggregation between the particles will change from a single dispersion to a cluster. All the above phenomena were in accordance with the requirements of nano-gold cold melt indicator. Therefore,the nano-gold sol prepared by using sodium alginate as a stabilizer is a good nano-gold cold-melt indicator.