Electrochemical nanosensor using MXene-carbon dot modified screen-printed carbon electrodes for creatinine detection in serum samples

Abstract

An innovative electrochemical (EC) nanosensor utilizing screen-printed carbon electrodes (SPCE) functionalised with MXenes (Ti3C2TX) and carbon dots (CDs) has been developed for the ultrasensitive sensing of CR in phosphate-buffered saline (PBS) and human serum samples. This novel SPCE@MXene@CDs configuration significantly enhanced redox signals, achieving excellent sensitivity with a 0.016 mg·dL-1 detection limit. The electrical conductivity of the SPCE@MXene@CDs sensor was enhanced by systematically optimizing four key parameters: scan rate, number of scan cycles, pH of the PBS buffer, and CDs concentration during fabrication. The nanosensor demonstrated outstanding selectivity with no interference from common metabolites (e.g., glucose, urea, ascorbic acid, glutathione, bovine serum albumin) and electrolytes (Ca2+, Mg2+, PO43-, SO42-). In addition, the nanosensor demonstrated a high correlation with the standard Jaffe method (R2 = 0.99) for CR detection in ultra-low serum volumes of 5 µL (n = 22). Our research findings underscore the potential of this nanosensor for rapid, highly sensitive, and point-of-care CR monitoring in complex biological environments.