Herein, a metal-free photoelectrochemical (PEC) cathodic biosensor based on a composite material of graphitic carbon nitride (g-C₃N₄) and a conjugated polymer of poly(3-hexylthiophene) (P3HT) is proposed. The formation of a p–n heterojunction between g-C₃N₄ and P3HT through π–π stacking induced a high degree of molecular ordering, efficient charge separation, and a significantly enhanced PEC performance. The g-C₃N₄/P3HT PEC cathodic sensor implements sensitive and selective detection of hydrogen peroxide secreted from living cells in a wide linear range from 1.0 to 800 μM with a limit of detection of 0.38 μM. We believed that the metal-free PEC cathodic detection strategy opens up an excellent biodetection approach with high biocompatibility.

中文翻译：

---

石墨化氮化碳/聚（3-己基噻吩）纳米复合材料用于光电化学检测活细胞中的H ₂ O ₂

在此，提出了基于石墨氮化碳（gC ₃ N ₄）与聚（3-己基噻吩）（P3HT）的共轭聚合物的复合材料的无金属光电化学（PEC）阴极生物传感器。通过π-π堆积在gC ₃ N ₄和P3HT之间形成ap-n异质结，导致高度的分子有序性，有效的电荷分离和显着增强的PEC性能。gC ₃ N ₄/ P3HT PEC阴极传感器可在1.0至800μM的宽线性范围内进行灵敏且选择性的检测活细胞分泌的过氧化氢，检测极限为0.38μM。我们相信，无金属的PEC阴极检测策略开辟了一种具有高生物相容性的出色生物检测方法。