**5. Conclusions**

In conclusion, we demonstrated the proof-of-concept of an innovative biosensor for the detection of bacteria through their lysate, by combining the use of both optically monitored porous silicon membranes and selective enzymatic lytic agents. We showed promising results in terms of sensitivity, specificity and speed of response by confirming the targeted detection of 10<sup>5</sup> CFU/ml of *B. cereus* lysate in only one hour. Furthermore, we illustrated the versatility of the detection platform by detecting selectively lysed *S. epidermidis*. These results, added to the easy fabrication and low design cost, pave the way for the development of a widespread multi-strain bacteria sensor.

**Author Contributions:** Conceptualization, R.V. and L.A.F.; methodology, R.V. and A.L.; software, R.V.; validation, R.V.; formal analysis, R.V.; investigation, R.V. and A.L.; resources, J.M. and L.A.F.; data curation, R.V.; writing—original draft preparation, R.V.; writing—review and editing, A.L., J.M., and L.A.F.; visualization, R.V.; supervision, J.M. and L.A.F.; project administration, J.M. and L.A.F.; funding acquisition, R.V., J.M., and L.A.F. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research was funded by National Fund for Scientific Research (FRIA gran<sup>t</sup> to R.V. and FNRS gran<sup>t</sup> to J.M.) and the Research Department of the Communauté française de Belgique (Concerted Research Action, ARC no.17/22-084, gran<sup>t</sup> to A.L.).

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

**Informed Consent Statement:** Not applicable.

**Data Availability Statement:** The data presented in this study are openly available in Zenodo at 10.5281/zenodo.4446911, reference number data.xlsx.

**Acknowledgments:** We would like to thank Jonathan Rasson for his help during the conceptualization stages of this project.

**Conflicts of Interest:** The authors declare no conflict of interest.
