Chongqing Key Laboratory of Green Synthesis and Applications, College of Chemistry , Chongqing Normal University , Chongqing 401331 , China.
Materials Genome Institute , Shanghai University , Shanghai 200444 , China.
Anal Chem. 2018 May 15;90(10):6247-6252. doi: 10.1021/acs.analchem.8b00885. Epub 2018 May 3.
The peroxidase-like catalytic activity of gold nanoclusters (Au-NCs) is quite low around physiological pH, which greatly limits their biological applications. Herein, we found heparin can greatly accelerate the peroxidase-like activity of Au-NCs at neutral pH. The catalytic activity of Au-NCs toward the peroxidase substrate 3,3',5,5'-tetramethylbenzidine (TMB) oxidation by HO was 25-fold increased in the presence of heparin at pH 7. The addition of heparin not only accelerated the initial catalytic rate of Au-NCs but also prevented the Au-NCs from catalyst deactivation. This allows the sensitive colorimetric detection of heparin at neutral pH. In the presence of heparinase, heparin was hydrolyzed into small fragments, weakening the enhancement effect of catalytic activity. On the basis of this phenomenon, the colorimetric determination of heparinase in the range from 0.1 to 3 μg·mL was developed with a detection limit of 0.06 μg·mL. Finally, the detection of heparin and heparinase activity in diluted serum samples was also demonstrated.
金纳米簇（Au-NCs）在生理 pH 下的过氧化物酶样催化活性相当低，这极大地限制了它们的生物应用。在此，我们发现肝素可以在中性 pH 下大大加速 Au-NCs 的过氧化物酶样活性。在 pH 7 下，肝素的存在使 Au-NCs 对过氧化物酶底物 3,3',5,5'-四甲基联苯胺（TMB）氧化的催化活性增加了 25 倍。肝素的加入不仅加速了 Au-NCs 的初始催化速率，而且防止了 Au-NCs 的催化剂失活。这使得在中性 pH 下可以灵敏地比色检测肝素。在肝素酶存在下，肝素被水解成小片段，从而削弱了催化活性的增强作用。基于这一现象，在肝素酶的浓度范围为 0.1 到 3 μg·mL 时，开发了一种检测限为 0.06 μg·mL 的比色测定法。最后，还证明了在稀释的血清样本中检测肝素和肝素酶活性的方法。
