A signal-off photoelectrochemical sandwich-type immunosensor based on WO3/TiO2 Z-scheme heterojunction

IF 5.3 2区化学 Q1 CHEMISTRY, ANALYTICAL

Microchimica Acta Pub Date : 2023-09-12 DOI:10.1007/s00604-023-05954-1

Fubin Pei, Shasha Feng, Wei Hu, Qingli Hao, Bing Liu, Xihui Mu, Wu Lei, Zhaoyang Tong

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引用次数: 0

Abstract

A sandwich “signal-off” type photoelectrochemical (PEC) immunosensor was fabricated based on a composite heterojunction of tungsten oxide/titanium oxide microspheres (WO₃/TiO₂) acting as signal amplification platform and carbon microspheres loaded by gold nanoparticles (Cs@Au NPs) utilized as the label for detecting antibody. WO₃/TiO₂ had excellent photoelectric performance, and the results of Mott-Schottky plots, open-circuit voltage, and electron spin resonance spectroscopy indicated that it belonged to the Z-scheme heterojunction transfer mechanism of photogenerated carriers. To achieve the sensitization of PEC immunosensor, Cs@Au NP–labeled immunocomplex can effectively reduce the photocurrent signal. The PEC immunosensors were fabricated under the optimal conditions of 1:1 WO₃/TiO₂ (molar ratio), 2.0 mg mL⁻¹ WO₃/TiO₂, and 1.5 mg mL⁻¹ Cs@Au NPs. Through comparison of the detection results of label-free and sandwich-type PEC immunosensors for nucleocapsid (N) protein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), we found that the sensitivity of the sandwich type was 2.53 times the label-free type, and the limit of detection was 0.006 ng mL⁻¹, i.e., 3.17 times lower than the label-free type. This demonstrates that the developed sandwich-type PEC immunosensor will have a brighter application prospect.

Graphical Abstract

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一种基于WO3/TiO2 Z型异质结的光电化学三明治型免疫传感器。

基于作为信号放大平台的氧化钨/氧化钛微球（WO3/TiO2）和负载金纳米颗粒的碳微球的复合异质结，制备了三明治“信号关闭”型光电化学（PEC）免疫传感器(Cs@AuNP）作为用于检测抗体的标记物。WO3/TiO2具有优异的光电性能，Mott-Schottky图、开路电压和电子自旋共振光谱的结果表明，它属于光生载流子的Z型异质结转移机制。为了实现PEC免疫传感器的增敏，Cs@AuNP标记的免疫复合物能有效降低光电流信号。PEC免疫传感器是在1:1 WO3/TiO2（摩尔比）、2.0 mg mL-1 WO3/TiO2和1.5 mg mL-1的最佳条件下制备的Cs@AuNP。通过比较无标记和三明治型PEC免疫传感器对严重急性呼吸综合征冠状病毒2型（SARS-CoV-2）核衣壳（N）蛋白的检测结果，我们发现三明治型的灵敏度是无标记型的2.53倍，检测限为0.006 ng/mL-1，即比无标记型低3.17倍。这表明所开发的三明治型PEC免疫传感器将具有更广阔的应用前景。

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来源期刊

Microchimica Acta 化学-分析化学

CiteScore

9.80

自引率

5.30%

发文量

410

审稿时长

2.7 months

期刊介绍： As a peer-reviewed journal for analytical sciences and technologies on the micro- and nanoscale, Microchimica Acta has established itself as a premier forum for truly novel approaches in chemical and biochemical analysis. Coverage includes methods and devices that provide expedient solutions to the most contemporary demands in this area. Examples are point-of-care technologies, wearable (bio)sensors, in-vivo-monitoring, micro/nanomotors and materials based on synthetic biology as well as biomedical imaging and targeting.