State Key Laboratory of Marine Resource Utilization in South China Sea, School of Materials Science and Engineering, Hainan University, Haikou 570228, China.
Department of Clinical Laboratory of the Second Affiliated Hospital, School of Tropical Medicine, Key Laboratory of Emergency and Trauma of Ministry of Education, Research Unit of Island Emergency Medicine, Chinese Academy of Medical Sciences (No. 2019RU013), Hainan Medical University, Haikou 571199, China.
Biosensors (Basel). 2023 Jul 7;13(7):714. doi: 10.3390/bios13070714.
A photoelectrochemical (PEC) detection platform was built based on the branched rutile/anatase titanium dioxide (RA-TiO) electrode. Theoretical calculations proved that the type-II band alignment of rutile and anatase could facilitate charge separation in the electrode. The self-generated electric field at the interface of two phases can enhance the electron transfer efficiency of the electrode. Carboxylated CdTe quantum dots (QDs) were applied as signal amplification factors. Without the target DNA presence, the CdTe QDs were riveted to the surface of the electrode by the hairpin probe DNA. The sensitization of CdTe QDs increased the photocurrent of the electrode significantly. When the target DNA was present, the structural changes of the hairpin probe DNA resulted in the failure of the sensitized structure. Benefiting from excellent electrode structure design and CdTe QDs sensitization strategy, the PEC assays could achieve highly sensitive and specific detection of target DNA in the range of 1 fM to 1 nM, with a detection limit of 0.23 fM. The electrode construction method proposed in this article can open a new avenue for the preparation of more efficient PEC sensing devices.
构建了基于树枝状锐钛矿/金红石二氧化钛（RA-TiO）电极的光电化学（PEC）检测平台。理论计算证明，金红石和锐钛矿的 II 型能带排列可以促进电极中的电荷分离。两相界面处的自生电场可以提高电极的电子转移效率。羧基化 CdTe 量子点（QD）被用作信号放大因子。在不存在靶 DNA 的情况下，发夹探针 DNA 将 CdTe QD 铆接在电极表面。CdTe QD 的敏化显著增加了电极的光电流。当存在靶 DNA 时，发夹探针 DNA 的结构变化导致敏化结构失效。得益于优异的电极结构设计和 CdTe QDs 敏化策略，PEC 分析能够在 1 fM 至 1 nM 的范围内实现对靶 DNA 的高灵敏度和特异性检测，检测限低至 0.23 fM。本文提出的电极构建方法为制备更高效的 PEC 传感设备开辟了新途径。
