Serum Creatinine Electrochemical Biosensor on Printed Electrodes Using Monoenzymatic Pathway to 1-Methylhydantoin Detection

[Image: see text] The rising prevalence of Chronic Kidney Disease (CKD) has necessitated efforts towards the development of cost-effective and accurate biosensors for serum creatinine, which is a potent biomarker reflecting kidney function. This work presents a novel and cost-effective technique to estimate serum creatinine without any sample preprocessing. The technique involves the conversion of creatinine by a monoenzymatic pathway to 1-methylhydantoin. The concentration of 1-methylhydantoin is then quantified by utilizing its innate ability to form a complex with transition metals such as cobalt. The complex formation has been validated using optical spectroscopy and the transmittance at 290 nm wavelength is used to identify the optimum concentration of cobalt chloride in sensing chemistry. This chemical assay is shown to be robust against interference from serum albumin, the abundant plasma protein that can potentially influence the sensor response. The electrochemical biosensor developed using screen-printed electrodes thus provides highly selective creatinine estimation over the range of 0.2–4 mg/dL in a sample volume of 300 μL with no preprocessing and hence can be easily translated into a viable point-of-care (POC) device.