Portable Electrochemical Platform for Point-of-Care Bilirubin Sensing for Liver Diagnostics

Elevated bilirubin serves as a subtle yet early indicator of liver dysfunction, highlighting the need for a rapid, accessible, and reliable point-of-care solution. To the best of our knowledge, this study presents the first portable electrochemical platform for point-of-care bilirubin sensing for liver diagnostics. The portable device features onboard power management and a customized analog front end with precise signal acquisition, conditioning, and filtering to support Cyclic Voltammetry (CV), Differential Potential Voltammetry (DPV), and amperometric techniques for the electrochemical detection of any analyte. Herein, the optimised gold nanoparticles/SPCE enables effective bilirubin adsorption and subsequent oxidation at ∼0.35 V. An analyte-selective nafion-chitosan membrane suppressed interferences, achieving a 0.3 μM detection limit at pH 7.4. The on-device detection was evaluated by utilising the standard electrochemical setup, followed by high selectivity, repeatability, and reproducibility. Real-sample testing revealed ∼9.5% deviation from clinical values, confirming strong agreement with conventional methods. The on-device bilirubin detection through the amperometry technique delivers results both on-device and via a wireless user interface. In the future, the developed device can potentially detect other bioanalytes with minor modifications in terms of suitable chemistry.