Founding Scientist - Protein Engineer

Hormones drive fertility, but we still measure them roughly the way we did decades ago with a blood draw at a clinic, or a urine stick test that gives you an isolated number. A cycle is a moving signal, and we're currently sporadically reading one data point every few days.

Oxense Bio is building a wearable monitor that tracks hormones continuously, in real time, from interstitial fluid, using the same matrix and the same amperometric architecture as a continuous glucose monitor. Our technology is based on a proprietary protein switch that translates a binding event into an electrochemical current we can measure. The sensing platform is target-agnostic, but we are focused on female hormones and fertility care as our first application, because we believe that is where continuous data is most overdue and most useful.

We're an early-stage R&D startup, meaning there are still open scientific challenges and the uncertainty that comes with an early-stage startup. We're hiring our founding technical hires, and you'll own a core piece of the platform, help set how the team works, and take meaningful equity alongside the real risk that comes with a company at this stage. If you want a tightly scoped role at an established firm, this position is probably not for you but if you're looking for a scientific challenge worth pursuing and giving your all to, let's talk!

The role is full-time and in-person in our lab in London.

What you'll own

The protein switch is at the heart of the technology, and you will be actively overseeing its development and incorporation into our sensor. We are collaborating with the inventors of the technology and you'll help design and engineer the protein chimeras that couple hormone binding to enzymatic activity, express and purify them, and push their performance. This means optimizing the binding dynamics and ensuring long-term stability as well as working with our bioelectrochemist on integrating the protein switches on our sensor electrodes.

Day to day

• Help design protein switches that couple a hormone‑binding domain to a redox enzyme so that binding gates catalytic activity, by rational design, directed evolution, library screening, or all three.


• Maximise the properties that matter for a sensor: dynamic range, affinity and selectivity across the target hormone panel, reversibility, and stability under operating conditions.


• Express recombinant proteins (E. coli and, where the domain demands it, eukaryotic systems), purify by chromatography, and QC every batch.


• Characterise hormone‑dependent behaviour: enzyme kinetics as a function of hormone, dose‑response, binding affinity and specificity by SPR, BLI, ITC or MST, plus thermostability and shelf‑life.


• Engineer for the real world, so switches keep working once they've been immobilised and protected by a membrane.


• Help set the protein roadmap on what to build next.


• Operate both as an independent contributor and a collaborative team member in an early‑stage startup environment, focusing on milestone‑driven research and development.

Required qualifications:

• A PhD in biochemistry, protein engineering, enzymology, molecular biology, chemical biology or a related field, or a Master's degree plus strong hands‑on experience.


• Competent in hands‑on recombinant protein expression and purification, start to finish.


• Experience with protein engineering by rational design and/or directed evolution, including library construction and screening.


• A confident grasp of enzyme kinetics and mechanism.


• Experience with binding characterisation by SPR, BLI, ITC, MST or equivalent.


• Fluent in molecular cloning.


• Outstanding teamwork and communication skills and the ability to work effectively in an interdisciplinary team and communicate with internal and external stakeholders.

Desired qualifications:

• Experience with allosteric proteins, engineered biosensors, or fusion and domain‑insertion designs that couple binding to activity.


• Experience with redox enzymes (oxidases, dehydrogenases) and their cofactors (FAD, PQQ, NAD(P)).


• Experience with using proteins for hormone or small‑molecule recognition: nuclear‑receptor ligand‑binding domains, or engineered binders such as nanobodies, DARPins or computationally designed proteins.


• Experience with computational protein design and structure prediction (Rosetta, AlphaFold and the tools built on it).


• Comfortable with high‑throughput screening and lab automation.

What we offer:

• Meaningful equity. You'll be a founding scientist and one of the first employees in a highly dynamic startup.


• A competitive cash salary set to your experience.


• Work that runs from bench science to a product people will actually wear.


• Full‑time, in‑person, London.