Electrochemical Biosensing and Direct Electron Transfer Techniques

Electrochemical biosensing integrates biological recognition elements with electrode transducers to convert biochemical interactions into measurable electrical signals. Central to third-generation devices is direct electron transfer, whereby redox-active sites within enzymes or haemoproteins communicate with the electrode surface without chemical mediators. Advances in electrode materials—from carbon nanotubes and metal nanoparticles to ionic liquids—have enhanced interfacial conductivity, increased biocompatibility and stabilised protein conformation. These improvements yield sensors with higher sensitivity, rapid response times and extended dynamic ranges. Applications span clinical diagnostics, environmental monitoring and food safety, where compact, low-cost devices deliver real-time analysis of analytes such as hydrogen peroxide, nitrite and small organic pollutants. By tailoring nanostructures and surface chemistries, researchers now achieve precise control over electron-transfer kinetics, electrocatalytic efficiency and sensor robustness, underpinning a new generation of portable, high-performance bioelectrochemical platforms.

Research from Nature Portfolio

Recent studies have demonstrated mediator-free direct electron transfer of myoglobin immobilised on gold nanoparticle-decorated carbon nanotube and polytyramine composites, achieving high surface coverage and electron-transfer rates that enable sensitive amperometric detection of hydrogen peroxide and nitrite with sub-micromolar detection limits. Another approach employed naphthyl-substituted amine functionalised ionic liquids covalently anchoring haemoproteins onto glassy carbon electrodes, preserving native protein structure and producing well-defined redox peaks with rapid electron exchange kinetics, thereby facilitating efficient electrocatalysis of bromate in neutral media. A further advancement introduced aza-heterocyclic receptors coordinated to haem iron centres, promoting direct electron transfer of haemoglobin on disposable carbon electrodes and enabling point-of-care measurement of blood samples with minimal interference and results within one minute.

Electrochemical Biosensing and Direct Electron Transfer Techniques publication trend

The graph below shows the total number of articles in electrochemical biosensing and direct electron transfer techniques across all publications each year (not limited to Nature Index journals).

Technical terms

Electrochemical biosensor: A device combining a biological recognition element with an electrochemical transducer to convert a biochemical event into an electrical signal.

Direct electron transfer: The unmediated exchange of electrons between the redox centre of an enzyme or haemoprotein and the electrode surface.

Mediator-free biosensor: A sensor design that omits artificial electron shuttles, relying instead on direct electrical communication with the biorecognition element.

Nanomaterial: A material featuring structural components at the nanometre scale, providing high surface area and enhanced electronic properties.

Electrocatalysis: Catalysis of an electrochemical reaction at an electrode surface by a biological or chemical catalyst, improving reaction kinetics.

References

1. Behind the Optimization of the Sensor Film: Bioconjugation of Triangular Gold Nanoparticles with Hemoproteins for Sensitivity Enhancement of Enzymatic Biosensors. Biosensors (2023).
2. Electrochemical Biosensor Based on Horseradish Peroxidase and Black Phosphorene Quantum Dot Modified Electrode. Molecules (2023).
3. Immobilization of myoglobin on Au nanoparticle-decorated carbon nanotube/polytyramine composite as a mediator-free H2O2 and nitrite biosensor. Scientific Reports (2015).
4. Rationally designed naphthyl substituted amine functionalized ionic liquid platform for covalent immobilization and direct electrochemistry of hemoglobin. Scientific Reports (2019).
5. Aza-heterocyclic Receptors for Direct Electron Transfer Hemoglobin Biosensor. Scientific Reports (2017).
6. Ionic liquid‐based materials for electrochemical biosensing. Clinical and Translational Discovery (2022).