A metal-free electrode using heteroatom-doped microporous carbon was fabricated for the ultrasensitive monitoring of mono-bioactive molecules and the selective signaling of dopamine (DA) secreted by living cells. The constructed electrode based on sulfur-doped microporous carbon (S-MC) shows a high surface area, a spherical construction, numerous carbon chain defects, and microporous structures, which are the key factors of the interactive signaling transducer, fast response, and active interfacial surfaces. The intrinsic features of S-MC with different %S-doping (S-MC-1, and S-MC-2) through the sp²-carbon chain create abundant catalytic active sites, facilitate molecular diffusion through the microporous structure, promote strong binding with the targeted molecules, and induce interactions at electrolyte–electrode interfaces. The S-MC-1 provides selective signaling in a tertiary mixture of DA, ascorbic acid (AA), and uric acid (UA) with a high sensitivity and a wide linear range of 0.01–5, 10–4000, and 1–2000 µM, respectively. The detection limits were set at 3 nM, 1.26 µM, and 0.23 µM for DA, AA, and UA respectively. The S-MC-1 demonstrated a selective screening of DA released from PC12 cells under a K⁺ ion- stimulator with high sensitivity and promoted high biocompatibility, low cytotoxicity, high stability, and reliable reproducibility (%RSD ranged from 1 to 2.7). Our findings indicated that the S-MC-1 can be utilized as an in-vitro model for simultaneously monitoring extracellular-DA secreted from living cells and sensing mono-bioactive molecules in biological samples.

制备了使用杂原子掺杂的微孔碳的无金属电极，用于超灵敏地监测生物活性分子和活细胞分泌的多巴胺（DA）的选择性信号。基于硫掺杂微孔碳（S-MC）构建的电极显示出高表面积，球形结构，许多碳链缺陷和微孔结构，这是交互式信号传感器，快速响应和活性的关键因素界面。通过sp ²具有不同％S掺杂（S-MC-1和S-MC-2）的S-MC的固有特征碳链可创建丰富的催化活性位点，促进分子通过微孔结构扩散，促进与目标分子的牢固结合，并诱导电解质-电极界面的相互作用。S-MC-1在DA，抗坏血酸（AA）和尿酸（UA）的三级混合物中提供选择性信号，具有高灵敏度和0.01–5、10–4000和1–2000的宽线性范围分别为µM。DA，AA和UA的检测限分别设置为3 nM，1.26 µM和0.23 µM。S-MC-1在K ⁺下展示了对PC12细胞释放的DA的选择性筛选高灵敏度的离子刺激剂，促进了高生物相容性，低细胞毒性，高稳定性和可靠的重现性（％RSD范围为1至2.7）。我们的发现表明，S-MC-1可以用作体外模型，用于同时监测活细胞分泌的细胞外DA并检测生物样品中的单生物活性分子。