9.6 million people died from cancer in 2018 alone. Traditionally, chemotherapeutic drugs are administered intravenously and circulate freely throughout the body. This inevitably kills healthy cells along with cancer cells, leading to some of the unwanted side effects of chemotherapy. Additionally, high dosage and systemic administration desensitises cancer cells, potentially leading to drug resistance. Our solution is to package the drug payload within lipid vesicles containing a membrane-embedded biosensor. The biosensor responds to the presence of cancer-associated proteases in the immediate vicinity of the tumour, selectively releasing the drug to kill cancer cells. This is achieved by a peptide-oligonucleotide conjugate (POC) that can trigger a downstream response to open a DNA nanopore. The biosensor could be customisable towards a variety of protein biomarkers and disease contexts. This novel cancer drug delivery system could minimise the proclivity towards drug resistance and side effects of future chemotherapy treatments.