Microneedle-based biosensing

Microneedles (MNs) are microscopic needles that are applied to the skin in a minimally invasive way to facilitate transdermal drug delivery and/or uptake of interstitial fluid from the skin, which contains a variety of metabolites that can serve as biomarkers. The collection of interstitial fluid can be followed by post-sampling analysis or in situ real-time biosensing for disease diagnosis and drug monitoring. The painless and easy administration of MNs is appealing to patients, especially for long-term monitoring. In this Review, we discuss the use of MNs for biosensing purposes. We highlight the different types of MNs and sensing technologies used to develop MN-based biosensors. In addition, we discuss the potential to integrate MNs with wearable devices for real-time monitoring to improve point-of-care testing. Finally, we review the translational hurdles to be considered in bringing this technology from benchtop to bedside.