A portable smartphone-based electrochemical sensing platform for rapid and sensitive detection of creatinine in blood serum †

Rayhan, Rifat and Haque Shishir, Md. Inzamamul and Khaleque, Md. Abdul and Amin, Md. Ruhul and Ali, Md. Romzan and Aly Saad Aly, Mohamed and Ayon, Shakib Mahmud and Saidur, Rahman and Han Kim, Tan and Zaed, Md. Abu and Hossain Khan, Md. Zaved (2025) A portable smartphone-based electrochemical sensing platform for rapid and sensitive detection of creatinine in blood serum †. RSC Advances, 15 (30). pp. 24917-24929. ISSN 2046-2069

Abstract

Muscle metabolism produces creatinine, a waste product whose levels in the blood and urine are crucial markers of kidney health. Herein, a smartphone-based electrochemical detection strategy was developed to quantify creatinine in human blood serum. Since creatinine was electrochemically inactive, a standard copper solution was added as an electro-activator to produce an electrochemically active creatinine–copper complex. At a pH of 7.4, the creatinine–copper composite was oxidized in a phosphate buffer solution (PBS). Electrochemical oxidation of the free Cu+ ion in PBS is tested by the surface modification of Ti2C2Tx@poly(l-Arg) nanocomposite. The analytical performance of the developed electrochemical sensor was evaluated by differential pulse voltammetry. The developed electrochemical sensor was evaluated using a combination of techniques: electrochemical methods like cyclic voltammetry and electrochemical impedance spectroscopy, morphological analysis with scanning electron microscopy, and structural analysis with attenuated total reflectance Fourier transform infrared spectroscopy and X-ray diffraction. Notably, the developed sensor demonstrated an impressively low detection limit of 0.05 μM and a linear range of 1–200 μM. Moreover, the sensor remarkably exhibited a stable creatinine detection response with an acceptable reproducibility for two two-week periods and demonstrated a robust immunity against interfering molecules. This is the first report on the synthesis of Ti2C2Tx@poly(l-Arg) nanocomposites and their application in the electrochemical detection of creatinine. This smartphone-based creatinine sensor offers a promising, rapid, and reliable technique for creatinine detection, with potential applications in clinical diagnostics and biomedical research, due to its high sensitivity, selectivity, and portability.