Delayed Sensor Activation Based on Transient Coatings: Biofouling Protection in Complex Biofluids

Transient polymeric coatings with a programmable transiency behavior are used for delayed exposure of fresh surfaces of multi-electrode sensor arrays at preselected times. Such delayed sensor actuation is shown to be extremely attractive for addressing severe biofouling characteristic of electrochemical biosensors in complex biofluids. Controlled coating dissolution and tunable sequential actuation of the individual sensing electrodes are achieved by tailoring the characteristics of the coating (density and thickness). The unique features offered by these delayed sensors allowed direct glucose monitoring in untreated blood and saliva samples over prolonged periods. This attractive delayed-sensor exposure concept, offering time-tunable sequential activation of multiple sensors with remarkable anti-biofouling properties, indicates considerable promise for operating sensors continuously in complex body fluids.