Microneedle coupled epidermal sensor for multiplexed electrochemical detection of kidney disease biomarkers

Early diagnosis of chronic kidney disease (CKD) and constant monitoring to guide optimal intervention is critical to prevent renal failure and other critical diseases. However, the conventional blood tests in hospital are time-consuming and have poor patient compliance. Herein, we demonstrate a real-time, minimally invasive, and self-administrable approach to detect kidney biomarkers in the skin interstitial fluid (ISF) using a polymeric microneedle coupled electrochemical sensor array (MNESA). Microneedles can readily penetrate stratum corneum and quickly extract ISF onto the sensors. Four biomarkers are simultaneously detected to avoid false positive and provide an accurate assessment of kidney functions. Using an artificial skin model, it is shown that MNSEA gives specific and sensitive responses to these kidney biomarkers in physiologically relevant ranges (phosphate: 0.3–1.8 mM, 3.62 μA/mM; uric acid: 50–550 μM, 4.19 nA/μM; creatinine: 50–550 μM, 12.58 nA/μM; urea: 1–16 mM, 44.6 mV/decade). Using a mouse model, we demonstrate that this approach is as reliable as the commercial assays and is feasible to readily monitor the progression of CDK.