金纳米微粒作探针共振瑞利散射光谱法测定亚甲蓝

Resonance Rayleigh Scattering Spectral Method for Determination of Methylene Blue with Gold Nanoparticle as Probe

在pH为6．5～9．5的中性或弱碱性介质中，金纳米微粒可与亚甲蓝（MB）阳离子靠静电引力及疏水作用力结合，形成粒径较大的聚集体（平均粒径从12nm增至20nm），这种聚集体的形成导致共振瑞利散射（RRS）强度显著增强，最大散射峰位于371nm．在适当条件下，散射强度（△I）与亚甲蓝浓度成正比．该法具有高灵敏度，将金纳米微粒作为测定亚甲蓝的高灵敏RRS探针，对亚甲蓝的检出限为21．17ng／mL，该法简便，快速，且有较好的选择性，可用于血液中亚甲蓝的测定．

In a neutral or weak alkaline medium（ pH = 6. 5-9.5 ）, the gold nanoparticle can combine with methylene blue by the virtue of electrostatic and hydrophobic interaction, forming aggregate with bigger diameters（ average diameter increase from 12 to 20 nm ）. The aggregate arouse Resonance Rayleigh Scattering （RRS） intensity enhancing greatly. The maximum scattering peaks are at 371 nm. Under optimum conditions, there is a linear relationship between scattering intensity（AI） and the concentration of methylene blue. This method has a high sensitivity. So gold nanoparticle can be used as the RRS probe of high sensitivity for methylene blue. The detection limit of methylene blue is 21.17 ng/mL. The method which is simple and rapid has good selectivity. It was successfully applied to the detection of methylene blue in clinic serum samples.