Aptamer protective material and biosensor

An analyte monitoring sensor configured for in vivo measurement of at least one analyte, comprising:

• a substrate having a substrate surface;
• a co-adsorbate coupled or tethered to the substrate surface and/or an aptamer protective layer encapsulating at least a portion of the substrate surface, the aptamer protective layer permeable to the at least one analyte;
• one or more aptamer conjugates associated with at least a portion of the substrate surface and positioned between the aptamer protective layer and the substrate for obtaining measurements related to the at least one analyte in vivo;
• and
• at least one reversible redox moiety coupled to at least one of the one or more aptamer conjugates.

A method of extending end of life of an electrochemical aptamer biosensor (EAB), the method comprising:

• associating at least one aptamer conjugate to a surface of a conductive substrate, the at least one aptamer conjugate comprising a reversible redox moiety;
• one or more co-adsorbates coupled or tethered to the substrate surface and/or encapsulating the at least one aptamer conjugate in an aptamer protective layer, the at least one aptamer conjugate configured to undergo a reversible confirmation change within the aptamer protective layer in response interaction with an analyte so as to generate a detectable signal;
• controlling one or more of:
• ionic strength, surface phase separation of the aptamer protective layer, and intermolecular interactions between the at least one aptamer conjugate and the aptamer protective layer;
• and
• extending the end-of-life of the electrochemical aptamer sensor.

An aptamer protective layer configured for transcutaneous in vivo continuous online monitoring, the aptamer protective layer comprising a polymer selected from:

• a functionalized polymer comprising at least one zwitterionic repeating group;
• a functionalized polymer from at least one of a polymerizable zwitterionic monomer structure as follows:
• where X is O, NH, or NR4, Y and Z are, independently, acyclic alkyl, substituted or unsubstituted heteroalkyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted and of which can be optionally substituted with OH, halogen, or alkoxyl;
• R1, R3, R4, and R5 are independently H, alkyl, heteroalkyl, cycloalkyl, cycloheteroalkyl, aryl, or heteroaryl;
• a functionalized polymer comprising alkanethiol, phenylthiol, or benzyl thiol groups;
• a functionalized polymer comprising alkanethiol groups, phenylthiol groups, or benzyl thiol groups in combination with zwitterionic repeating groups;
• a functionalized polymer comprising mercaptoalkanol groups, arylmercaptoalkanol groups, benzylmercaptoalkanol groups, or mixtures thereof;
• a functionalized polymer comprising mercaptoalkanol groups, arylmercaptoalkanol groups, benzylmercaptoalkanol groups or mixtures thereof in combination with zwitterionic repeating groups;
• or
• a segmented multiblock polymer.

A method of determining an in vivo concentration of an analyte, the method comprising:

• contacting, in vivo, a biological fluid comprising an analyte with an electrochemical aptamer biosensor comprising an aptamer conjugate;
• a conductive substrate;
• a co-adsorbate associated with both the aptamer conjugate and the conductive substrate;
• and/or an aptamer protective layer encapsulating the aptamer conjugate about the conductive substrate, the aptamer protective layer being permeable to an analyte, the electrochemical aptamer biosensor producing a signal upon interaction with the analyte;
• and
• interrogating the conductive substrate or the electrochemical aptamer;
• and
• detecting the signal corresponding to an in vivo concentration of the analyte.