Investigating the impact of copper-PEDOT:PSS matrix towards nonenzymatic electrochemical creatinine detection

Electrochemical creatinine sensors offer great promise toward rapid, reagent-free, and point-of-care (POC) kidney-function monitoring. However, challenges related to analyte binding, data reproducibility, sensitivity, fouling, and device degradation deter their widespread implementation. Here, we show how a carbon electrode modified with a combination of poly(3,4-ethylene dioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) and copper nanoparticles (CuNPs) can rapidly and accurately detect creatinine (CT) in artificial urine media employing electrochemical techniques. Applying redox potential sweeps (vs Ag/AgCl) using copper sulfate (CuSO4) solution on such a sensor facilitates the CuNP embedding process inside the conjugated polymer matrix, which has been further validated by supporting techniques. We predicted and validated the formation and contribution of two Cu–CT ion-exchange matrix interactions corresponding to Cu(I) and Cu(II) states, which are responsible for CT detection. The fabricated CT sensor exhibits high selectivity against major artificial urine interferents and is stable for a month, showing minimal degradation (1.87%) in peak current value. Such sensors can be utilized to detect and monitor different stages of renal failure in real-time patient samples.