Abstract：
The combination of closed bipolar electrodes (cBPE) with electrochemiluminescence (ECL) imaging has demonstrated remarkable capabilities in the field of bioanalysis. Here, we established a cBPE-ECL platform for ultrasensitive detection of alkaline phosphatase (ALP) and two-dimensional imaging of epidermal growth factor receptor (EGFR). This cBPE-ECL system consists of a high-density gold nanowire array in anodic aluminum oxide (AAO) membrane as the cBPE coupled with ECL of highly luminescent cadmium selenide quantum dots (CdSe QDs) luminophores to achieve cathodic electro-optical conversion. When an enzyme-catalyzed amplification effect of ALP with 4-aminophenyl phosphate monosodium salt hydrate (p-APP) as the substrate and 4-aminophenol (p-AP) as the electroactive probe is introduced, a significant improvement of sensing sensitivity with a detection limit as low as 0.5 fM for ALP on the cBPE-ECL platform can be obtained. In addition, the cBPE-ECL sensing system can also be used to detect cancer cells with an impressive detection limit of 50 cells/mL by labeling ALP onto the EGFR protein on A431 human epidermal cancer cell membranes. Thus, two-dimensional (2D) imaging of the EGFR proteins on the cell surface can be achieved, demonstrating that the established cBPE-ECL sensing system is of high resolution for spatiotemporal cell imaging.
摘要：
封闭双极电极（cBPE）与电化学发光（ECL）成像的组合在生物分析领域已显示出卓越的能力。这里,我们建立了超灵敏检测碱性磷酸酶(ALP)和表皮生长因子受体(EGFR)二维成像的cBPE-ECL平台.该cBPE-ECL系统由阳极氧化铝（AAO）膜中的高密度金纳米线阵列组成，作为cBPE与高发光硒化镉量子点（CdSeQD）发光体的ECL耦合，以实现阴极电光转换。当引入以4-氨基苯基磷酸一钠盐水合物（p-APP）为底物和4-氨基苯酚（p-AP）为电活性探针的ALP的酶催化扩增作用时，可以在cBPE-ECL平台上获得感测灵敏度的显着提高，ALP的检出限低至0.5fM。此外,cBPE-ECL传感系统还可用于通过将ALP标记到A431人表皮癌细胞膜上的EGFR蛋白上来检测50细胞/mL的令人印象深刻的检测极限的癌细胞。因此，可以实现细胞表面EGFR蛋白的二维（2D）成像，证明已建立的cBPE-ECL传感系统具有高分辨率的时空细胞成像。
