Stabilizer-free preparation of titanium-based nanowires combined with copper for sensitive detection of 2,4,5-trihydroxybenzoic acid: application in edible oil samples

2,4,5-Trihydroxybenzoic acid (THBA) is a synthetic antioxidant used in the food industry that has attracted attention due to the potential risks it may pose to human health; thus, ensuring compliance with legal standards is essential. In this regard, the present study describes the development of an electrochemical platform based on a carbon-printed electrode (SPE) modified with titanium (Ti)-based nanowires (NWs) for THBA detection. However, the synthesis of Ti-based NWs involved varying copper (Cu) quantities, resulting in few morphological changes compared to the unmodified counterpart. Interestingly, the syntheses were carried out without organic stabilizers, resulting in the preparation of cleaner nanostructures; such an approach was planned to enhance the electrochemical sensing performance, reduce costs, and promote environmental friendliness. Moreover, it improves charge transfer efficiency, making the synthesis process ideal for sustainable nanomaterial production. XRD analyses indicate that the addition of the metal affected the structure of the Ti-based NWs. Also, SEM images revealed that the unmodified SPE exhibited a smooth surface, whereas the Cu-modified Ti-based NWs/SPE showed a dense network of such material. In addition, the electrochemical studies have shown an enhancing of the electrocatalytic properties after the introduction of copper. Under optimized conditions, it was found that THBA can be determined over a wide working range from 500 pmol L⁻¹ to 5000 µmol L⁻¹. The applicability of the sensor was verified by detecting THBA in soybean oil and sunflower oil samples, showing excellent recovery values between 96.30 and 101.87%, suggesting that the proposed sensor demonstrates good accuracy and can be successfully applied to edible oil samples.