Ng Shu Rui, O'Hare Danny
Department of Bioengineering, Imperial College London, UK SW7 2AZ.
Analyst. 2015 Jun 21;140(12):4224-31. doi: 10.1039/c5an00377f. Epub 2015 Apr 28.
pH sensors were fabricated by anodically electrodepositing iridium oxide films (AEIROFs) onto microelectrodes on chips and coated with poly(ethyleneimine) (PEI) for mechanical stability. These demonstrate super-Nernstian response to pH from pH 4.0 to 7.7 in chloride-free phosphate buffer. The surface of the chip was coated with fibronectin for the attachment of porcine aortic endothelial cells (PAECs). The working capability of the pH sensor for monitoring acute local pH changes was investigated by stimulating the PAECs with thrombin. Our results show that thrombin induced acute extracellular acidification of PAECs and dissolution of fibronectin, causing the local pH to decrease. The use of PD98059, a mitogen-activated protein kinase (MAPK) inhibitor, reduced extracellular acidification and an increase in local pH was observed. This study shows that our pH sensors can facilitate the investigation of acute cellular responses to stimulation by monitoring the real-time, local pH changes of cells attached to the sensors.
通过在芯片上的微电极上阳极电沉积氧化铱薄膜（AEIROFs）并涂覆聚亚乙基亚胺（PEI）以提高机械稳定性来制造pH传感器。这些传感器在无氯磷酸盐缓冲液中对pH 4.0至7.7表现出超能斯特响应。芯片表面涂有纤连蛋白以附着猪主动脉内皮细胞（PAECs）。通过用凝血酶刺激PAECs来研究pH传感器监测急性局部pH变化的工作能力。我们的结果表明，凝血酶诱导PAECs急性细胞外酸化和纤连蛋白溶解，导致局部pH降低。使用丝裂原活化蛋白激酶（MAPK）抑制剂PD98059可减少细胞外酸化，并观察到局部pH升高。这项研究表明，我们的pH传感器可以通过监测附着在传感器上的细胞的实时局部pH变化，促进对刺激的急性细胞反应的研究。
