Sampling Dermal Interstitial Fluid Using Microneedles: A Review of Recent Developments in Sampling Methods and Microneedle‐Based Biosensors

Abstract Although interstitial fluid (ISF) is recognized as an important source of biomarkers, it is difficult and time‐consuming to extract, thus limiting its use in medical diagnostic and clinical settings. An inexpensive and effective technique for accessing ISF could benefit people with various health conditions and offer platforms for on‐device sensing biomarkers. Microneedles (MNs) are minimally invasive devices that have gained extensive interest over recent decades. MNs can address some of the challenges associated with ISF extraction and sensing. Accessing ISF using MNs has the potential to develop advanced, non‐invasive point‐of‐care (POC) microdevices that enable detection or continuous monitoring within the dermal ISF, therefore drastically impacting the healthcare system. This review describes recent studies exploring MN devices for ISF sampling and sensing. Several extraction processes, sampling volume, sampling duration, integration with biosensors, sensing of biomarkers, and subsequent analysis of ISF are discussed in detail. Furthermore, opportunities, conclusions, and future prospects for developing new research in the field are also discussed.