title: Evaluation of a minimally invasive glucose biosensor for continuous tissue monitoring.
abstract: We describe here a minimally invasive glucose biosensor based on a microneedle array electrode fabricated from an epoxy-based negative photoresist (SU8 50) and designed for continuous measurement in the dermal compartment with minimal pain. These minimally invasive, continuous monitoring sensor devices (MICoMS) were produced by casting the structures in SU8 50, crosslinking and then metallising them with platinum or silver to obtain the working and reference electrodes, respectively. The metallised microneedle array electrodes were subsequently functionalised by entrapping glucose oxidase in electropolymerised polyphenol (PP) film. Sensor performance in vitro showed that glucose concentrations down to 0.5 mM could be measured with a response times (T90) of 15 s. The effect of sterilisation by Co60 irradiation was evaluated. In preparation for further clinical studies, these sensors were tested in vivo in a healthy volunteer for a period of 3-6 h. The sensor currents were compared against point measurements obtained with a commercial capillary blood glucometer. The epoxy MICoMS devices showed currents values that could be correlated with these. Graphical Abstract Microneedle arrays for continuous glucose monitoring in dermal interstitial fluid.
authors.affiliation: Department of Chemistry & Institute of Biomedical Engineering, Imperial College, South Kensington Campus Exhibition Road, London, SW7 2AY, UK. sanjiv.sharma@imperial.ac.uk.
authors.forename: Sanjiv
authors.identifier: http://orcid.org/0000-0003-3828-737X
authors.initials: S
authors.lastname: Sharma
authors.affiliation: Department of Bioengineering, Imperial College, South Kensington Campus, London, SW7 2AZ, UK.
authors.forename: Zhenyi
authors.initials: Z
authors.lastname: Huang
authors.affiliation: Department of Bioengineering, Imperial College, South Kensington Campus, London, SW7 2AZ, UK.
authors.forename: Michelle
authors.initials: M
authors.lastname: Rogers
authors.affiliation: Department of Bioengineering, Imperial College, South Kensington Campus, London, SW7 2AZ, UK. m.boutelle@imperial.ac.uk.
authors.forename: Martyn
authors.initials: M
authors.lastname: Boutelle
authors.affiliation: Department of Chemistry & Institute of Biomedical Engineering, Imperial College, South Kensington Campus Exhibition Road, London, SW7 2AY, UK. t.cass@imperial.ac.uk.
authors.forename: Anthony E G
authors.initials: AE
authors.lastname: Cass
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods; D004563:Electrochemistry; D004566:Electrodes; D004867:Equipment Design; D045604:Extracellular Fluid / Q000737:chemistry*; D005947:Glucose / Q000032:analysis*; D064368:Healthy Volunteers; D006801:Humans; D008845:Microinjections; D008991:Monitoring, Physiologic / Q000295:instrumentation* / Q000379:methods; D009339:Needles; D011108:Polymers; D012867:Skin / Q000737:chemistry*
chemical_list: D011108:Polymers; D005947:Glucose
keywords: Continuous glucose monitoring (CGM); Electrochemical sensor; Microneedles