海藻酸钠复合水凝胶的制备及其细菌检测应用研究

Preparation of sodium alginate composite hydrogel for bacterial detection

目的制备海藻酸钠-金纳米颗粒复合水凝胶并研究其检测细菌的性能,为可视化细菌检测创伤敷料的开发奠定基础。方法以海藻酸钠为原料,掺杂显色底物氯酚红β-D-吡喃半乳糖苷及半乳糖苷酶修饰的金纳米颗粒,通过钙离子引发的海藻酸钠交联制备复合水凝胶,研究其对细菌的检测性能。结果当金纳米颗粒尺寸为5 nm,浓度为100 nmol/L时,水相中传感器对大肠杆菌和金黄色葡萄球菌的检测限可达100 CFU/mL;复合凝胶对金黄色葡萄球菌的检测限可达1000 CFU/mL。结论海藻酸钠-金纳米颗粒复合水凝胶具有生物相容性好、细菌检测灵敏度高的优点,有望作为伤口敷料用于检测伤口愈合过程中的细菌感染。

Objective Sodium alginate-gold nanoparticle composite hydrogels were prepared and their performances in detecting bacteria were studied,which lay a foundation for the development of visualized bacterial detection for wound dressings.Methods Sodium carboxyalginate were doped with chromogenic substrate chlorophenol redβ-D-galactopyranoside and galactosidase-modified gold nanoparticles,and were crosslinked to form the hydrogel under the induction of Ca2+.Subsequently,the capability of bacterial detection was studied.Results The limit of detection for Escherichia coli and Staphylococcus aureus in the aqueous phase was determined as 100 CFU/mL when the concentration of 5 nm gold nanoparticles was 100 nmol/L.The detection limit of composite gel for Staphylococcus aureus was as low as 1000 CFU/mL.Conclusion Sodium alginate-gold nanoparticle composite hydrogel had the advantage of good biocompatibility and high sensitivity for bacterial detection,which held great promise as a wound dressing for detecting bacterial infections during wound healing.