title: Integrated hollow microneedle-optofluidic biosensor for therapeutic drug monitoring in sub-nanoliter volumes.
abstract: Therapeutic drug monitoring (TDM) typically requires painful blood drawn from patients. We propose a painless and minimally-invasive alternative for TDM using hollow microneedles suitable to extract extremely small volumes (<1 nL) of interstitial fluid to measure drug concentrations. The inner lumen of a microneedle is functionalized to be used as a micro-reactor during sample collection to trap and bind target drug candidates during extraction, without requirements of sample transfer. An optofluidic device is integrated with this microneedle to rapidly quantify drug analytes with high sensitivity using a straightforward absorbance scheme. Vancomycin is currently detected by using volumes ranging between 50-100 μL with a limit of detection (LoD) of 1.35 μM. The proposed microneedle-optofluidic biosensor can detect vancomycin with a sample volume of 0.6 nL and a LoD of <100 nM, validating this painless point of care system with significant potential to reduce healthcare costs and patients suffering.
authors.affiliation: Department of Electrical and Computer Engineering, University of British Columbia, Vancouver, BC V6T 1Z4, Canada.|Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, BC V6T 1Z3, Canada.|Laboratory for Micro- and Nanotechnology, Paul Scherrer Institute, 5232 Villigen PSI, Switzerland.
authors.forename: Sahan A
authors.initials: SA
authors.lastname: Ranamukhaarachchi
authors.affiliation: Laboratory for Micro- and Nanotechnology, Paul Scherrer Institute, 5232 Villigen PSI, Switzerland.
authors.forename: Celestino
authors.initials: C
authors.lastname: Padeste
authors.affiliation: Laboratory for Micro- and Nanotechnology, Paul Scherrer Institute, 5232 Villigen PSI, Switzerland.
authors.forename: Matthias
authors.initials: M
authors.lastname: Dübner
authors.affiliation: Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, BC V6T 1Z3, Canada.
authors.forename: Urs O
authors.initials: UO
authors.lastname: Häfeli
authors.affiliation: Department of Electrical and Computer Engineering, University of British Columbia, Vancouver, BC V6T 1Z4, Canada.|Department of Mechanical Engineering, University of British Columbia, Vancouver, BC V6T 1Z4, Canada.
authors.forename: Boris
authors.initials: B
authors.lastname: Stoeber
authors.affiliation: Laboratory for Micro- and Nanotechnology, Paul Scherrer Institute, 5232 Villigen PSI, Switzerland.
authors.forename: Victor J
authors.initials: VJ
authors.lastname: Cadarso
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D001786:Blood Glucose / Q000032:analysis; D016903:Drug Monitoring / Q000379:methods*; D045604:Extracellular Fluid / Q000737:chemistry / Q000187:drug effects*; D006801:Humans; D009339:Needles; D019095:Point-of-Care Systems; D013048:Specimen Handling
chemical_list: D001786:Blood Glucose