E-AB biosensors as basis for controlled drug delivery. Feedback-controlled drug delivery for continuous drug administration with dosage levels based on integrating E-AB signal calculations into a drug administering medical device. E-AB biosensors do not require reagents, are inexpensive compared to antibody detection methods, can be used in blood or other fluids with high abundance of non-target molecules, and they are reusable. These are all factors that make E-AB biosensors a promising method for feedback-controlled drug delivery dependent on integrated calculations of computer programming.