Design considerations of a hollow microneedle-optofluidic biosensing platform incorporating enzyme-linked assays

Sahan A. Ranamukhaarachchi, Celestino Padeste, Urs O. Hafeli, Boris Stoeber, Victor J. Cadarso

Research output: Contribution to journalArticleResearchpeer-review

10 Citations (Scopus)


A hollow metallic microneedle is integrated with microfluidics and photonic components to form a microneedle-optofluidic biosensor suitable for therapeutic drug monitoring (TDM) in biological fluids, like interstitial fluid, that can be collected in a painless and minimally-invasive manner. The microneedle inner lumen surface is bio-functionalized to trap and bind target analytes on-site in a sample volume as small as 0.6 nl, and houses an enzyme-linked assay on its 0.06 mm2 wall. The optofluidic components are designed to rapidly quantify target analytes present in the sample and collected in the microneedle using a simple and sensitive absorbance scheme. This contribution describes how the biosensor components were optimized to detect in vitro streptavidin-horseradish peroxidase (Sav-HRP) as a model analyte over a large detection range (0-7.21 μM) and a very low limit of detection (60.2 nM). This biosensor utilizes the lowest analyte volume reported for TDM with microneedle technology, and presents significant avenues to improve current TDM methods for patients, by potentially eliminating blood draws for several drug candidates.

Original languageEnglish
Article number024002
Number of pages9
JournalJournal of Micromechanics and Microengineering
Issue number2
Publication statusPublished - 1 Feb 2018
Externally publishedYes


  • biosensor
  • enzyme-linked assay
  • hollow microneedle
  • optofluidic sensing
  • therapeutic drug monitoring

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