Carbon dot-based imprinted electrochemical sensor for ultrasensitive and selective detection of sucralose in real samples

Abstract

One of the most widely used artificial non-nutritive sweeteners in food is sucralose (SC), which provides sweetness with few or no calories. For monitoring its concentration in foodstuffs, a novel selective and sensitive electrochemical sensor was developed using carbon dots (CDs) and synthetic molecularly imprinted polymers (MIPs) on the surface of a glassy carbon electrode (GCE). Density functional theory (DFT) was used not only to screen potential monomers for polymerization but also to investigate the interactions of the SC molecules with the proposed monomers. The outstanding selectivity of the sensor stems from the synthesized imprinted polymers. The 3D cavities in the polymer surface originated from the physical interaction between SC and methyl methacrylate and acrylamide monomers. The synthesized imprinted polymers were thoroughly examined using EDX spectroscopy, AFM, FTIR spectroscopy, SEM, TEM, BET analysis, and elemental mapping analysis. In addition, the electrochemical behavior of the synthesized sensors was then described by means of electrochemical impedance spectroscopy and cyclic voltammetry. The innovative platform exhibited good selection for SC molecules in the presence of other coexisting species, cost-effectiveness, and ease of use. In addition, it showed good sensitivity (2.04 × 10⁻¹⁰ mol L⁻¹) with a wide linear range (6.2 × 10⁻¹⁰–7.1 × 10⁻³ mol L⁻¹), superior constancy (7 weeks), and high precision (RSD = 3.4%). As a result, the proposed imprinted sensor was effectively utilized to detect SC, using differential pulse voltammetry, in food and beverage samples with outstanding recoveries (98.8–100.0%).