Department of Applied Pharmaceutical Sciences and Clinical Pharmacy, Faculty of Pharmacy, Isra University, P.O. Box 33, Amman 11622, Jordan.
Faculty of Pharmacy, Philadelphia University, P.O. Box 1, Amman 19392, Jordan.
Sensors (Basel). 2023 Oct 13;23(20):8453. doi: 10.3390/s23208453.
Measurement of the intracellular pH is particularly crucial for the detection of numerous diseases, such as carcinomas, that are characterised by a low intracellular pH. Therefore, pH-responsive nanosensors have been developed by many researchers due to their ability to non-invasively detect minor changes in the pH of many biological systems without causing significant biological damage. However, the existing pH-sensitive nanosensors, such as the polyacrylamide, silica, and quantum dots-based nanosensors, require large quantities of organic solvents that could cause detrimental damage to the ecosystem. As a result, this research is aimed at developing a new generation of pH-responsive nanosensors comprising alginate natural polymers and pH-sensitive fluorophores using an organic, solvent-free, and ecologically friendly method. Herein, we successfully synthesised different models of pH-responsive alginate nanoparticles by varying the method of fluorophore conjugation. The synthesised pH nanosensors demonstrated a low MHD with a relatively acceptable PDI when using the lowest concentration of the cross-linker Ca (1.25 mM). All the pH nanosensors showed negative zeta potential values, attributed to the free carboxylate groups surrounding the nanoparticles' surfaces, which support the colloidal stability of the nanosensors. The synthesised models of pH nanosensors displayed a high pH-responsiveness with various correlations between the pH measurements and the nanosensors' fluorescence signal. In summation, pH-responsive alginate nanosensors produced using organic, solvent-free, green technology could be harnessed as potential diagnostics for the intracellular and extracellular pH measurements of various biological systems.
细胞内 pH 值的测量对于许多疾病的检测尤其重要，例如癌症，其特征是细胞内 pH 值较低。因此，许多研究人员开发了 pH 响应纳米传感器，因为它们能够非侵入性地检测许多生物系统中 pH 的微小变化，而不会造成显著的生物损伤。然而，现有的 pH 敏感纳米传感器，如聚丙烯酰胺、硅和量子点基纳米传感器，需要大量的有机溶剂，这可能会对生态系统造成有害的破坏。因此，本研究旨在开发新一代的 pH 响应纳米传感器，该传感器由海藻酸钠天然聚合物和 pH 敏感荧光团组成，使用有机、无溶剂和环保的方法。在此，我们通过改变荧光团缀合的方法成功合成了不同模型的 pH 响应海藻酸钠纳米粒子。当使用最低浓度的交联剂 Ca（1.25mM）时，所合成的 pH 纳米传感器表现出低的 MHD 和相对可接受的 PDI。所有 pH 纳米传感器都显示出负的 zeta 电位值，这归因于围绕纳米粒子表面的游离羧酸盐基团，这支持了纳米传感器的胶体稳定性。所合成的 pH 纳米传感器模型表现出高的 pH 响应性，pH 测量和纳米传感器荧光信号之间存在各种相关性。总之，使用有机、无溶剂、绿色技术生产的 pH 响应海藻酸钠纳米传感器可以作为各种生物系统的细胞内和细胞外 pH 测量的潜在诊断工具。
