Smartphone-interfaced blood plasma-creatinine level detection using a manually operated hand driven centrifuge integrated with paper-strip sensor

Abstract

Detecting blood plasma creatinine at the point of care is challenging due to the need for high sensitivity and accuracy in a complex biological matrix, alongside the difficulty of miniaturizing laboratory techniques into portable, affordable devices, including the means for plasma separation from whole blood samples. Additional hurdles include interference from other compounds, operator variability, and maintaining reliability under diverse environmental conditions. Here, we envisage a power-free, miniature, point of care adaptation of the laboratory-centric Jaffe reaction based biochemical procedure, introducing a mechanically operated hand-driven centrifuge as a smart solution for controlled sample separation. This is followed by colorimetric detection of the target analyte using a smartphone-interfaced paper-strip sensor. The method is demonstrated for detecting blood plasma creatinine levels, a key marker for chronic kidney disease progression. An in-house smartphone application (“CRE-SENSE” app) coordinates the sample-to-answer process, achieving a detection limit of 0.022 mM and an analytical range of 0.03–0.50 mM for creatinine from a finger-prick blood sample. Benchmarking against gold-standard laboratory procedures, this platform technology offers an affordable, accessible solution for highly accurate blood plasma creatinine level diagnostics at resource-constrained locations where the availability of electric power is limited and other auxiliary facilities for clinical pathology are scarce. Such highly accurate point-of-care tests for blood plasma creatinine may potentially improve early detection, treatment decisions, and patient outcomes while enhancing accessibility, operational efficiency, and cost-effectiveness in kidney function monitoring and personalized care. © 2025 Elsevier B.V.