A borophene electrocatalyst for the identification of calcium ions in blood serum samples

Abstract

Calcium (Ca²⁺) ions are vital electrolytes in neuromuscular function, cardiovascular regulation, bone health, blood clotting, and cellular signalling. This makes their accurate detection crucial for diagnosing conditions such as hyperparathyroidism, kidney disease, and metabolic disorders. This study develops a borophene-based electrochemical sensor that enables rapid, highly sensitive, and selective monitoring of calcium levels, offering significant advancements in clinical diagnostics and personalized healthcare. The sensor leverages borophene's exceptional electrocatalytic properties and ability to facilitate rapid ion transport, enhancing charge transfer kinetics at the fabricated sensor interface. Various analytical techniques, including powder Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM), were used to examine the morphological and physicochemical characteristics of borophene. These methods provided comprehensive insights into the crystallinity, functional groups, surface morphology, and nanoscale structural features, ensuring a thorough characterization of the material's composition and behaviour. Electrochemical characterisation using differential pulse voltammetry (DPV) and cyclic voltammetry (CV) demonstrates a broad linear detection range (LDR) (0.29–1.0 μM), an ultra-low detection limit (LOD) and quantification limits (LOQs) of 0.09 μM and 0.29 μM, as well as excellent repeatability. Additionally, the sensor exhibits a strong anti-interference performance against competing physiological ions, ensuring high specificity. Integrating borophene into electrochemical biosensing highlights its potential for next-generation point-of-care diagnostics, paving the way for the miniaturized, real-time monitoring of essential biomarkers in biomedical applications.