ultra-low-hydrogen-peroxide-detection-via-synergistic-nernst

Ultra-Low Hydrogen Peroxide Detection via Synergistic Nernst Potential Effect in Organic Electrochemical Transistors

The organic electrochemical transistor (OECT)-based synergistic Nernst potential&#8212;generated via the Pt gate electrode catalyzing hydrogen peroxide ...

Taiyuan University of Technology

With the advantages of miniaturization, simple device structure, and fast response, the organic electrochemical transistor (OECT) has become an emerging platform for developing wearable enzyme sensors for real-time health monitoring. The floating gate (FG) OECT employs a distinct signal acquisition and amplification structure, mitigating the effects of non-specific physical adsorption during the sensing process and preventing contamination of the electrolyte solution by side reaction products. The current work reports a feasible wearable enzyme sensor using a poly(benzimidazobenzophenanthroline) (BBL)-Nafion-enzyme-Nafion stacking structure as the sensing layer of the FG OECT. Based on the experimental results, the BBL film with an area of 3.14 mm and a thickness of 175 nm can generate an open circuit potential of 199.61 mV in 10 M hydrogen peroxide compared with the blank control. Then, the FG OECT is integrated with the flexible microfluidic systems for on-skin detection of glucose, lactate, and uric acid with sensitivities of 92.47, 152.15, and 74.27 µA·dec, respectively. This FG OECT-based wearable enzyme sensor will open new windows for multiplexed detection of sweat metabolites.

A wearable enzyme sensor enabled by the floating-gate OECT with poly(benzimidazobenzophenanthroline) as the catalytic layer.

The food processing industry and biomedical science research are relying on the low limit of detection (LOD) for hydrogen peroxide (HO). Organic electrochemical transistors (OECTs) are excellent for biochemical sensing applications due to their excellent signal amplification capability. The paper describes  a way of detecting HO through the use of stacked poly(3,4-ethylenedioxythiophene): bromothymol blue (PEDOT: BTB)/poly(3,4-ethylenedioxythiophene): polystyrene sulfonate (PEDOT: PSS) as the semiconducting channel of the OECT. The HO sensor presents an ultra-low LOD, down to 1.8 × 10 M, due to the synergistic effect of the Nernst potential generated by the platinum gate electrode catalyzing HO and the Nernst potential generated by the interaction between BTB molecules and hydrogen ions, the by-product of HO catalysis. A microsystemwith a signal processing circuit and a mobile app for the sensor has been developed, and they are then tested on commercial milk samples to verify their reliability. Since the majority of enzyme-catalyzed reactions generate or use HO in biochemical reactions, the methodology is applicable not only to the detection of HO but also to the detection of analytes based on enzyme-catalyzed reactions. For demonstration, glucose detection with a LOD of down to 8.82 × 10 M is also presented.

Ultra-low LOD HO Sensor Based on Synergistic Nernst Potential Effect.

The sensitive and efficient detection of ochratoxin A (OTA) is critical for protecting agricultural ecosystems and public health. A dual-mode plasmonic colorimetric/photothermal aptasensor, based on a Mn-powered DNA walker for mediating gold nanobipyramid (AuNB) growth, is proposed for OTA detection in this study. In sensing the target OTA, the walking DNA (W-DNA) on the magnetic walker probe was independent and then the environment-friendly Mn powered the generation of DNAzyme, where abundant thiol-modified DNA (DNA-SH) was produced by autonomous walking. The positively related DNA-SH level could mediate AuNB growth and reflect dual-mode plasmonic signals. Ultrasensitivity is demonstrated with a limit of detection (LOD) value of 48.6 pg mL for colorimetric mode and 37.6 pg mL for photothermal mode. The aptasensor exhibited high specificity (with cross-reactivity values below 6.2% for other analytes) and high reliability for OTA detection. The requisite practicability and accessibility are verified via its application in agricultural byproduct samples. The findings of this study offer an alternative and efficient biosensing pathway for improving detection performance, enabling green, enzyme-free, homogeneous, and dual-mode strategies for monitoring other pollutants.

Article	Year
A wearable enzyme sensor enabled by the floating-gate OECT with poly(benzimidazobenzophenanthroline) as the catalytic layer. Journal of nanobiotechnology\| PubMed ID: 39972358	2025
Ultra-low LOD HO Sensor Based on Synergistic Nernst Potential Effect. Advanced science (Weinheim, Baden-Wurttemberg, Germany)\| PubMed ID: 40245293	2025
Dual-Mode Plasmonic Colorimetric/Photothermal Aptasensor for OTA: Based on a Mn-Powered DNA Walker for Mediating AuNB Growth. Foods (Basel, Switzerland)\| PubMed ID: 41227737	2025

Xiaojie Chai

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