Photoelectrochemical Sensing and Biosensing Technologies

Photoelectrochemical (PEC) sensing exploits semiconductor materials to convert light into electrical signals in response to chemical or biological interactions at an electrode surface. By tailoring band structures, surface architectures and interfaces, PEC platforms achieve high sensitivity, low background noise and, in some designs, self-powered operation. Advances in nanostructure engineering—such as heterojunctions, inverse opal scaffolds and two-dimensional composites—have driven significant improvements in charge separation, light absorption and bioreceptor immobilisation. Coupling PEC transduction with selective recognition elements, including antibodies, nucleic acids and enzyme labels, has yielded a diverse range of assays for small molecules, proteins and genetic targets. Recent trends focus on miniaturisation, point-of-care integration and signal‐amplification strategies that exploit upconversion nanoparticles, photocatalytic cascades or CRISPR-based cleavage to achieve ultrasensitive, rapid diagnostics across environmental, food-safety and clinical applications.

Research from Nature Portfolio

Engineered p–n heterostructures of p-type Cu2O and n-type ZnO nanorods have been shown to produce elevated photocurrents under visible illumination, enabling self-powered detection of biomolecules such as glutathione with broad dynamic range and excellent selectivity. Researchers have demonstrated that optimising carrier concentration in Cu2O raises interfacial electric fields and enhances photogenerated charge separation, leading to robust PEC biosensing at zero bias. Macroporous ZnO inverse opal electrodes modified with Ag2S nanoparticles extend light absorption into the long-wavelength region and align energy levels across the ZnO/Ag2S interface. This architecture supports the sensitive and rapid detection of alpha-fetoprotein over nanogram-per-millilitre concentrations, with high reproducibility and stability. Visible-light PEC immunosensors based on SnS2@mesoporous g-C3N4 composites have realised ultralow detection limits for prostate-specific antigen down to the femtogram-per-millilitre level. The overlapping band structures of SnS2 and g-C3N4 foster efficient charge-carrier separation, while the label-free format translates antibody binding events into quantifiable photocurrent decreases over a wide concentration range.

Photoelectrochemical Sensing and Biosensing Technologies publication trend

The graph below shows the total number of articles in photoelectrochemical sensing and biosensing technologies across all publications each year (not limited to Nature Index journals).

Technical terms

Photoelectrochemical sensing: A detection method that converts light-induced redox reactions at a semiconductor interface into electrical signals.

Photocurrent: The electric current generated by separation of photoexcited charge carriers under illumination.

Heterojunction: An interface between two semiconductors with distinct band structures that promotes charge-carrier separation.

Immunosensor: A biosensor that employs antigen–antibody binding to achieve selective detection of target proteins or biomarkers.

Upconversion nanoparticle (UCNP): A rare-earth-doped material that absorbs low-energy photons and emits higher-energy light, used for signal amplification under near-infrared excitation.

References

1. Electronic Structure Engineering of Cu2O Film/ZnO Nanorods Array All-Oxide p-n Heterostructure for Enhanced Photoelectrochemical Property and Self-powered Biosensing Application. Scientific Reports (2015).
2. Photoelectrochemical detection of alpha-fetoprotein based on ZnO inverse opals structure electrodes modified by Ag2S nanoparticles. Scientific Reports (2016).
3. Visible-light driven Photoelectrochemical Immunosensor Based on SnS2@mpg-C3N4 for Detection of Prostate Specific Antigen. Scientific Reports (2017).
4. A universal CRISPR-Cas14a responsive triple-sensitized upconversion photoelectrochemical sensor. Journal of Nanobiotechnology (2023).
5. Smartphone-Based Photoelectrochemical Immunoassay with Co9S8@ZnIn2S4 for Point-of-Care Diagnosis of Breast Cancer Biomarker. Research (2022).
6. In situ formation of (001)TiO2/Ti3C2 heterojunctions for enhanced photoelectrochemical detection of dopamine. Electrochemistry Communications (2021).