PT - JOURNAL ARTICLE AU - Hanjia Zheng AU - Amin GhavamiNejad AU - Peyman GhavamiNejad AU - Melisa Samarikhalaj AU - Adria Giacca AU - Mahla Poudineh TI - A Hydrogel Microneedle-assisted Assay Integrating Aptamer Probes and Fluorescence Detection for Reagentless Biomarker Quantification AID - 10.1101/2021.10.14.464448 DP - 2021 Jan 01 TA - bioRxiv PG - 2021.10.14.464448 4099 - http://biorxiv.org/content/early/2021/10/15/2021.10.14.464448.short 4100 - http://biorxiv.org/content/early/2021/10/15/2021.10.14.464448.full AB - Analyzing interstitial fluid (ISF) via microneedle (MN) devices enables patient health monitoring in a minimally invasive manner and at point-of-care settings. However, most MN-based diagnostic approaches require complicated fabrication processes or post-processing of the extracted ISF. Here we show in-situ and on-needle measurement of target analytes by integrating hydrogel microneedles (HMN) with aptamer probes as the target recognition elements. Fluorescently tagged aptamer probes are chemically attached to the hydrogel matrix while a crosslinked patch is formed. We use the assay for specific and sensitive quantification of glucose concentrations in an animal model of diabetes to track hypoglycemia, euglycemia, and hyperglycemia conditions. The assay can track the rising and falling concentrations of glucose and the extracted measurements closely match those from the gold standard techniques. The assay enables rapid and reagentless target detection and can be readily modified to measure other target analytes in vivo. Our system has the potential to improve the quality of life of patients who are in need of close monitoring of biomarkers of health and disease.Competing Interest StatementThe authors have declared no competing interest.