School of Chemistry and Chemical Engineering , University of Jinan , Jinan , Shandong 250022 , PR China.
Shandong Provincial Key Laboratory of Preparation and Measurement of Building Materials , University of Jinan , Jinan , Shandong 250022 , PR China.
Anal Chem. 2020 Feb 18;92(4):2902-2906. doi: 10.1021/acs.analchem.9b05611. Epub 2020 Feb 6.
Efficient separation of electron-hole pairs is vitally crucial to enhancing the analytical performance of paper-based photoelectrochemical (PEC) bioanalysis. Herein, a simple but effective strategy is developed to modulate the effective separation of photogenerated electrons and holes via introducing a polar charge carriers-created (PCC) electric field induced by a classical perovskite ferroelectric BaTiO (BTO). By inserting it between the n-type WO nanoflakes and p-type CuO (WO nanoflakes/BTO/CuO), the photoelectrode is endowed with a renewable PCC electric field, as a sustaining driving force, to guarantee the realization of directional separation of charge carrier (DSCC) strategy in PEC bioanalysis. The enduring PCC electric field can attract the electrons of CuO and holes of WO, respectively, thereby regulating the directional migration of charge carriers and achieving an enhanced PEC photocurrent for the ultrasensitive quantification based on the highly efficient separation of electron-hole pairs. Consequently, with respect to WO nanoflakes/CuO and WO nanoflakes photoelectrode, the polarized WO nanoflakes/BTO/CuO photoelectrode exhibits 1.7 and 10.9 times higher photocurrent density, respectively. Benefiting from this, the prominent photocurrent density is obtained which is extremely beneficial for enhancing the sensitivity of PEC bioanalysis. Ultimately, the ultrasensitive detection of model prostate specific antigen (PSA) is realized and presents a linear range of 0.1 pg/mL-50 ng/mL with the detection limitation of 0.036 pg/mL. This work provides the basis for understanding the role of the polarized electric field induced by ferroelectric in tuning the charge separation as well as insights on strategies for constructing high-performance paper-based PEC bioanalysis.
高效分离电子-空穴对对于提高基于纸的光电化学（PEC）生物分析的分析性能至关重要。本文提出了一种简单而有效的策略，通过引入经典钙钛矿铁电体 BaTiO（BTO）产生的极性载流子创建（PCC）电场来调制光生电子和空穴的有效分离。通过将其插入 n 型 WO 纳米片和 p 型 CuO（WO 纳米片/BTO/CuO）之间，光电电极具有可再生的 PCC 电场，作为持续的驱动力，以保证在 PEC 生物分析中实现载流子定向分离（DSCC）策略。持久的 PCC 电场可以分别吸引 CuO 的电子和 WO 的空穴，从而调节载流子的定向迁移，并基于高效的电子-空穴对分离实现增强的 PEC 光电流，用于超灵敏定量。因此，与 WO 纳米片/CuO 和 WO 纳米片光电电极相比，极化 WO 纳米片/BTO/CuO 光电电极分别表现出 1.7 和 10.9 倍更高的光电流密度。受益于此，获得了突出的光电流密度，这对于增强 PEC 生物分析的灵敏度极为有利。最终，实现了对模型前列腺特异性抗原（PSA）的超灵敏检测，其线性范围为 0.1 pg/mL-50 ng/mL，检测限为 0.036 pg/mL。这项工作为理解铁电体诱导的极化电场在调节电荷分离中的作用提供了基础，并为构建高性能基于纸的 PEC 生物分析策略提供了思路。
