Ultrasensitive Paper-Based Photoelectrochemical Sensing Platform Enabled by the Polar Charge Carriers-Created Electric Field

Abstract

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 BaTiO3 (BTO). By inserting it between the n-type WO3 nanoflakes and p-type Cu2O (WO3 nanoflakes/BTO/Cu2O), 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 Cu2O and holes of WO3, 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 WO3 nanoflakes/Cu2O and WO3 nanoflakes photoelectrode, the polarized WO3 nanoflakes/BTO/Cu2O 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.

Advanced Signal-Amplification Strategies for Paper-Based Analytical Devices: A Comprehensive Review

“…Photoelectrochemical (PEC) detection has drawn increasing attention due to its promising analytical features, including low cost, simple equipment, portability, persuasive selectivity and sensitivity, and low background, facilitating high-throughput and quick assays [ 117 , 118 , 119 , 120 ]. Driven by these advantages, paper-based PEC systems that integrate the inherited excellence of cellulose paper and PEC bioanalysis have been fabricated [ 117 ].…”

“…Photoelectrochemical (PEC) detection has drawn increasing attention due to its promising analytical features, including low cost, simple equipment, portability, persuasive selectivity and sensitivity, and low background, facilitating high-throughput and quick assays [ 117 , 118 , 119 , 120 ]. Driven by these advantages, paper-based PEC systems that integrate the inherited excellence of cellulose paper and PEC bioanalysis have been fabricated [ 117 ]. The PEC platform stems from the electrochemical ideal, which can convert light energy into chemical and electrical energy, hence ameliorating sensitive detection through the modification of photocurrent responses into photoelectrochemical reactions based on analytes and specific photoactive matrix/probe interactions [ 117 , 121 , 122 ].…”

“…Driven by these advantages, paper-based PEC systems that integrate the inherited excellence of cellulose paper and PEC bioanalysis have been fabricated [ 117 ]. The PEC platform stems from the electrochemical ideal, which can convert light energy into chemical and electrical energy, hence ameliorating sensitive detection through the modification of photocurrent responses into photoelectrochemical reactions based on analytes and specific photoactive matrix/probe interactions [ 117 , 121 , 122 ]. Photoactive electrons can be stimulated upon excitation by light, and conveyed to an electrode to generate a vigorous photocurrent signal, for which a signal-off or signal-on readout method is employed [ 117 , 122 ].…”

Modulating Charge Carrier Efficient Separation Enabled by Lewis Base Modification in Paper‐based Photoelectrochemical Sensor

“…Most importantly, combining both the advantages of paper strip tests and microfluidics, paperbased analytical devices can be perfectly compatible with POCT [9]. Among them, microfluidic paper-based photoelectrohemical (PEC) sensor which employs the completely separated light excitation source and photocurrent detection signal has made a great progress [10][11][12]. In general terms, the sensitivity of paper-based PEC sensor depends intimately on the photoelectric conversion performance of the utilized photoactive material, ascribing to that the analyte was detected by monitoring the change of obtained photocurrent responses [13].…”

Performance and Mechanism of Photoelectrocatalytic Activity of MoSx/WO3 Heterostructures Obtained by Reactive Pulsed Laser Deposition for Water Splitting

“…Among these factors are the optical properties of nanomaterials, their electronic structure, and the catalytic properties for activating the evolution of hydrogen and oxygen in aqueous solutions [4][5][6][7]. In the formation of hybrid/nanocomposite and hetero/multilayer structures, these factors affect the generation and transfer of non-equilibrium charge carriers (photogenerated electrons/holes) in semiconductors, the lifetime of these carriers, and the efficiency of catalytically activated processes of water splitting [8][9][10].…”