Zinc vacancy mediated electron–hole separation in ZnO nanorod arrays for high-sensitivity organic photoelectrochemical transistor aptasensor

Abstract

Schematic diagram of the response mechanism (A) and the construction (B) of the OPECT aptasensor.

Signal Modulation of Organic Photoelectrochemical Transistor by a Z-Scheme Photocathodic Gate: An Innovative Dual Amplification Strategy for Sensitive Aptasensing Application

“…Organic electrochemical transistor (OECT), on the basis of the modulated channel conductivity by the ionic injection from the electrolyte, is especially desirable due to its advantages, including excellent environmental stability, being conducive to miniaturization, and especially, an extremely high signal amplification ability. − Generally, the extra input gate bias potential ( V G ) is essential during the OECT process, which is disadvantageous for reducing power consumption . Inspired by the conversion of the noninvasive and clean stimulus of light to the electricity energy in the PEC process, several organic photoelectrochemical transistor (OPECT) sensors have been proposed by the combination of OECT and PEC strategies. − In the OPECT process, the light-induced voltage could not only principally save the power supply to make the device simplified but also permit the zero-gate-biased operation for its promising applications. − For instance, Wang’s group fabricated an OPECT sensor with zero gating voltage based on poly­(3,4-ethylenedioxythiophene) doped with poly­(styrenesulfonate) (PEDOT/PSS) channel and Fe-metal organic framework@PEDOT (Fe-MOF@PEDOT) photogate, which exhibited a 100-fold enhanced channel signal; as a result, the OPECT sensor had a better sensitivity than the general PEC method for target detection . Due to the amplification capability of the OPECT device composed by a UiO-66-NH 2 /CdS quantum dots (QDs) gate and a PEDOT/PSS channel, Gao et al constructed an efficient OPECT sensor for microRNA-166a detection with a low limit of detection (LOD) of 1.0 fM, which was 1 order of magnitude lower than the common PEC sensors under the same conditions .…”

Novel metalloporphyrin covalently functionalized polyphosphazene nanotubes for boosting the hydrogen evolution reaction

“…The favorable HER reaction kinetics of CoTPP-PZSNT is further revealed by the Nyquist plot, where the diameter of the semicircle is positively correlated with the charge transfer resistance of the electrocatalyst. [32][33][34] As shown in Fig. 4f, the diameter of the Nyquist plot of CoTPP-PZSNT is significantly smaller than that of NiTPP-PZSNT, CoTPP, and NiTPP, indicating the lowest charge transfer impedance and an enhancement of the HER reaction kinetics.…”

Synergistic effect of surface metal vacancies and Schottky junction on high-transconductance organic photoelectrochemical transistor aptasensing

“…As an advanced class of organic electronic building blocks, which combines organic electrochemical transistor (OECT) and photoelectrochemical (PEC) bioanalysis, organic photoelectrochemical transistors (OPECT) exhibit all the key requirements for bioelectronics, including low power consumption, mechanical softness, biocompatibility and stability in physiological environments, which is appropriate for biochemical and bioelectrical sensing. [1][2][3][4] In summary, OPECT operation involves the modulation of the channel conductivity in the OECT upon volumetric ion injection from the electrolyte into the polymeric channel, inheriting its inherent amplification capability and high sensitivity. 5 Transconductance (g m = DI DS /DV G ) 6 is one of the pivotal parameters and is relevant to the sensitivity of the device.…”