Recent advances and challenges: Translational research of minimally invasive wearable biochemical sensors

Wearable diagnostic devices that continuously monitor biomarkers of interest can significantly improve disease outcome. However, there is currently a lack of commercially available wearable biochemical health devices. Many of the commercially available devices are limited to monitoring the body's physical parameters. Even though there has been progress in the development of minimally invasive wearable biochemical sensors (WBS), many challenges hinder their real-life implementation. In this review, we focus on studies that have evaluated the sensor's performance in vivo, classified as level 4 of the technology readiness level (TRL), to identify and understand the important technological factors and strategies towards the actualization of wearable biosensors. We first discuss recent progresses of WBS categorized by the transducers and target biofluid. Through comparative analysis, we show that sensor performance depends highly on the sensing element design such that the choice of bioreceptor, incorporation of nanomaterial, and surface area modifications have a profound effect on sensitivity, linear range, and stability. We observed that correctional analysis may be required to account the effect of external factors that can influence the sensor performance. Furthermore, translating in vitro sensor characterization is successful when monitoring simple biofluids, but personalized calibration that correlates the sensor response to a reference technique was observed to be the best method to accurately determine biomarker concentrations. By focusing on studies with validated in vivo experiments (compared to standard techniques), we assess how various design strategies influence the WBS’ in vivo performance. © 2023 The Authors