**4. Conclusions**

In the present study, a photoelectrochemical sensor based on WO3 was constructed to detect *Listeria monocytogenes*. When pathogenic bacteria were present, the quantum dots fell off the surface of the electrode, causing the photocurrent to decrease. At the same time, combined with the shearing effect of Exo I, the photocurrent was significantly reduced, thereby amplifying the signal changes before and after the addition of pathogenic bacteria and increasing the detection limit. Finally, the performance of the sensing platform was verified through the aspects of specificity, stability, and repeatability. Under the optimal conditions, a range of 1.3 × 10<sup>1</sup> to 1.3 × 10<sup>7</sup> CFU/mL was observed, with a detection limit of 45 CFU/mL. This method may have hopeful prospects for the rapid detection of *Listeria monocytogenes*.

**Author Contributions:** Methodology, formal analysis, investigation, writing—original draft, L.Z.; conceptualization, supervision, writing—review and editing, H.H.; visualization, C.D.; methodology, H.G., S.J. and G.Z.; validation, J.B.; resources, S.Y.; supervision, H.H. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research was funded by the National Key Research and Development Program of China (2019YFC1605901), the Science and Technology Program of Liaoning Provincial Education Department (J2020049), and Liaoning Province's Program for Promoting Liaoning Talents (XLYC1808034).

**Institutional Review Board Statement:** Not applicable.

**Informed Consent Statement:** Not applicable. **Data Availability Statement:** The datasets generated for this study are available on request to the corresponding author.

**Conflicts of Interest:** The authors declare that they have no conflicts of interest.
