Jongsung Kim

This study reports a novel electrochemical approach for selective dopamine (DA) sensing. DA is a potential neurological biomarker for human aging and other neurodegenerative disorders, particularly Alzheimer's disease. The sensor is constructed using titanium‐based MXene and quercetin (Qu)‐loaded liposome functionalized with gold nanoparticles (AuNPs) (MXene/Lip‐Qu@AuNPs). MXene/Lip‐Qu@AuNPs is coated on a glassy carbon electrode (GCE) for DA sensing. The MXene provides high conductivity for electrochemical measurements of DA. The modified GCE is employed for DA sensing against various interferants, including ascorbic acid, aspartic acid, arginine, and cysteine. The proposed MXene/Lip‐Qu@AuNP‐based GCE exhibits sufficient detection limits of 0.35 and 0.72 μM for DA sensing using cyclic voltammetry and differential pulse voltammetry methods within a linear concentration range of 1–10 μM, respectively. The proposed sensor is used to detect DA in human serum samples. Hence, the proposed novel sensor is highly convenient and provides highly selective and sensitive DA detection.