Cyclodextrin-EDA-lysine sensor for salicylic acid in food samples

In this work, we present a novel electrochemical sensing platform based on cyclodextrin-ethylenediamine coupled lysine conjugate electropolymerized onto a pencil graphite electrode for the highly sensitive detection of salicylic acid in pickled fruits and aloe vera juice. The unique combination of the proposed sensor exploits the molecular recognition ability of cyclodextrin, while the ethylenediamine-lysine backbone enhances electron transfer and film integrity. The developed sensor possessed exceptional performance, achieving a limit of detection of 0.48 μM, a limit of quantification of 1.63 μM, a broad linear detection range from 5 μM to 2600 μM and sensitivity of 18 μA/μM/cm2. The practical applicability of the developed sensor was validated through real sample analysis of salicylic acid in pickled fruits and aloe vera juice using the standard addition method. The method exhibited excellent accuracy with recovery values ranging from 98% to 100%. Beyond offering a cost-effective and reliable strategy for detecting harmful preservatives in foods, this work paves the way for the development of next-generation host-guest electrochemical sensors tailored for real-time, on-site food safety screening.