Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou 215163, People's Republic of China.
Jinan Guoke Medical Technology Development Co., Ltd, Shandong, People's Republic of China.
Analyst. 2024 Aug 5;149(16):4276-4282. doi: 10.1039/d4an00764f.
A photoelectrochemical (PEC) biosensor with a wide linear detection range was developed for the sensitive detection of neuron-specific enolase (NSE), which was achieved by applying a photocurrent polarity transition strategy mediated by quercetin. The coupling reaction between Cr(VI) and quercetin drives the signal polarity from anodic to cathodic. When only quercetin is present in the test solution, photogenerated electrons are transferred to the electrode to generate anodic photocurrent. However, in the presence of the target, the signal probe released Cr(VI), which interacted with quercetin, and the electron transfer direction was changed to achieve signal polarity conversion. Meanwhile, protoporphyrin-sensitized Bi:SrTiO nanocubes were used as matrix photoactive materials to provide basic photocurrent. The doping of Bi element would adjust the bandgap of SrTiO, and the organic-inorganic composite material exhibits good photostability and chemical stability that can maintain stable photoelectric properties over a long period of time. Such a novel signal polarity transition strategy greatly broadened the sensor detection to the range of 0.00007-170 ng mL and obtained a relatively low detection limit (25 fg mL), which greatly improved the detection sensitivity and accuracy of the biosensor.
研制了一种光电化学（PEC）生物传感器，该传感器具有较宽的线性检测范围，可用于灵敏检测神经元特异性烯醇化酶（NSE），其通过应用槲皮素介导的光电流极性转换策略实现。Cr(VI)与槲皮素的偶联反应驱动信号极性从阳极到阴极。当测试溶液中仅存在槲皮素时，光生电子会转移到电极上，产生阳极光电流。然而，在存在靶标的情况下，信号探针释放出与槲皮素相互作用的 Cr(VI)，电子转移方向发生变化，从而实现信号极性转换。同时，原卟啉敏化的 Bi:SrTiO 纳米立方体制备为基质光活性材料，提供基本的光电流。Bi 元素的掺杂可以调整 SrTiO 的能带隙，而有机-无机复合材料表现出良好的光稳定性和化学稳定性，可以在长时间内保持稳定的光电性能。这种新型的信号极性转换策略大大拓宽了传感器的检测范围至 0.00007-170ng mL，并获得了相对较低的检测限（25fg mL），极大地提高了生物传感器的检测灵敏度和准确性。
