A polydopamine imprinted array on a binder-free carbon cloth assembled by gold carbon quantum dots as a portable flexible 3D nano-electrochemical sensor for selective trace monitoring of orlistat (xenical)

[Display omitted] •Trace orlistat detection by an imprinting strategy.•One step hydrotermally synthetize AuCDs used for surface modifying.•Carbon cloth as a binder-free portable flexible 3D material used as the working electrode.•Box-Behnken experimental design used to multivariable optimization of proposed sensor. One of the cutting-edge emerging approaches being used by researchers in the field of sensors is to go beyond conventional techniques and design flexible, portable, selective sensors that can swiftly and accurately identify trace quantities of target molecules. In this research, carbon cloth (CC) as a binder-free 3D flexible material, served as the working electrode. In a single-step, hydrothermal approach AuCD nanoparticles were synthetized and used to modify the CC surface. The molecular imprinting polymer approach using in situ electropolymerization of dopamine (DA) in the presence of orlistat (OST) utilized to fabricate imprinted sensor. The surface response (Box-Behnken) methodology was used to optimize the parameters affecting the electrode performance. In the conditions of pH = 8, DA to OST ratio = 2.5, cycle number = 30, KOH = 3.5 M, elution time = 20.4 min, and 0.0005 to 1.3 nM linear range with a detection limit of 0.0002 nM, the best response was obtained for the accurate identification of the OST. The stability, selectivity, and performance of the presented sensor were evaluated under optimal conditions. Using blood serum and urine samples, satisfactory outcomes were achieved in real samples. This is the first electrochemical sensor report for OST detection to date.