Key Laboratory of Luminescence Analysis and Molecular Sensing (Southwest University), Ministry of Education, Chongqing Engineering Laboratory of Nanomaterials & Sensor Technologies, College of Chemistry and Chemical Engineering, Southwest University, Chongqing, 400715, PR China.
Key Laboratory of Luminescence Analysis and Molecular Sensing (Southwest University), Ministry of Education, Chongqing Engineering Laboratory of Nanomaterials & Sensor Technologies, College of Chemistry and Chemical Engineering, Southwest University, Chongqing, 400715, PR China.
Talanta. 2024 Dec 1;280:126669. doi: 10.1016/j.talanta.2024.126669. Epub 2024 Aug 3.
In this work, a photoelectrochemical (PEC) immunosensor was constructed for the ultrasensitive detection of lung cancer marker neuron-specific enolase (NSE) based on a microflower-like heterojunction of cadmium indium sulfide and magnesium indium sulfide (CdInS/MgInS, CMIS) as photoactive material. Specifically, the well-matched energy level structure and narrow energy level gradients between CdInS and MgInS could accelerate the separation of electron-hole (e-h) pairs in the CMIS heterojunction to enhance the photocurrent of CMIS, which was increased 5.5 and 80 times compared with that of single CdInS and MgInS, respectively. Meanwhile, using CMIS as photoactive material, increasing the biocompatibility by dropping Pt NPs on the surface of CMIS to immobilize the antibody through Pt-N bond. FeO-Ab, acting as the quencher, competitively consumes electron donors and absorbs light, leading to photocurrent quenching. With the increasing of quencher, the photocurrent decreased. Hence, the developed "signal-off" PEC immunosensor realized the trace detection of NSE within the range from 1.0 fg/mL to 10 ng/mL with a low detection limit of 0.34 fg/mL. This strategy provided a new perspective for establishing ternary metal sulfide heterojunction to construct PEC immunosensor for sensitive detection of disease biomarkers.
在这项工作中，构建了基于硫化镉铟和硫化镁铟（CdInS/MgInS，CMIS）微花状异质结的光电化学（PEC）免疫传感器，用于超灵敏检测肺癌标志物神经元特异性烯醇化酶（NSE）。具体而言，CdInS 和 MgInS 之间匹配的能级结构和狭窄的能级梯度可以加速 CMIS 异质结中电子-空穴（e-h）对的分离，从而增强 CMIS 的光电流，与单独的 CdInS 和 MgInS 相比，光电流分别增加了 5.5 和 80 倍。同时，利用 CMIS 作为光活性材料，通过在 CMIS 表面滴加 Pt NPs 来提高生物相容性，通过 Pt-N 键固定抗体。FeO-Ab 作为猝灭剂，通过消耗电子供体和吸收光来竞争，导致光电流猝灭。随着猝灭剂的增加，光电流减小。因此，所开发的“信号关闭”PEC 免疫传感器实现了痕量 NSE 的检测，检测范围为 1.0 fg/mL 至 10 ng/mL，检测限低至 0.34 fg/mL。该策略为建立三元金属硫化物异质结以构建用于灵敏检测疾病生物标志物的 PEC 免疫传感器提供了新的视角。
