Flexible Screen-Printed Electrochemical Sensor for Alkaline Phosphatase Detection in Biofluids for Biomedical Applications

Alkaline phosphatase (ALP) is an enzyme present in the human body responsible for the dephosphorylation of phosphorylated chemical species. It is primarily expressed in organs such as bones, liver, intestine, and placenta during pregnancy, playing a crucial role in cellular processes like gene expression, transport, and metabolism. Physiological ALP levels vary with age and sex, with normal serum ranges for healthy adults between 40 and 190 U/L. Alterations in ALP levels can be indicative of several pathologies, including cancer diagnosis and metastasis, as well as bone growth dysfunctions and hypophosphatasia. Conventional methods for ALP detection often require complex assay principles, extensive sample pretreatment, and trained personnel. Herein, the development of a portable, flexible electrochemical sensor fabricated through screen-printing to monitor ALP levels in biological samples is introduced. The flexible electrochemical sensor, characterized by high efficiency, sustainability, low cost, and ease of disposal, achieves detection limit as low as 0.03 and 0.08 U/L, respectively, in buffer solution and human serum samples, and a satisfactory repeatability lower than 10%. This simple sensor configuration approach enables real-time disease monitoring and improves access to point-of-care diagnostics, paving the way for affordable, decentralized sensors that support early diagnosis and better healthcare.