Surface-enhanced Raman spectroscopy (SERS) has emerged as a powerful analytical tool for ultrasensitive detection of environmental contaminants, particularly pesticides. Recent developments have focused on nanomaterials engineering and SERS-active sensors to enhance signal intensity. Gold (AuNPs) and silver nanoparticles (AgNPs) of various morphologies and sizes have been widely explored due to their plasmonic properties, as well as hybrid or combined nanoparticle systems. Innovative approaches have also been developed, such as embedding nanoparticles in gels to enhance stability and reproducibility or using magnetic nanoparticles for sample interaction and preconcentration. Additionally, the integration of graphene oxide has gained attention because of its ability to improve the chemical enhancement mechanism via π–π interactions with analyte molecules. Despite these advances, SERS-based detection remains challenging, particularly with regard to selectivity in complex matrices. To address this issue, recent strategies have combined SERS substrates with biorecognition molecules such as antibodies, aptamers, and enzymes, thereby improving specificity and facilitating the development of SERS-based biosensors. This review highlights the current state-of-the-art SERS applications for pesticide detection in food and environmental samples, discussing the key technological advances, material innovations, and analytical challenges. This paper also offers perspectives on future research directions to increase the sensitivity, reproducibility, and field applicability of SERS-based detection platforms.

This work presents an optimization of the construction, treatment, and activation of 3D-printed electrochemical sensors (E-3D). For this, was used a 2³-full factorial design examining three key variables at two levels: electrode height, electrode diameter, and printing speed. Moreover, it evaluates various physical, chemical, and electrochemical methods to treat and activate the E-3D surface. The techniques of electrochemical impedance spectroscopy and cyclic voltammetry (CV) shows that the sequential physical, chemical, and electrochemical treatments lead to the highest treatment efficiency and activation. Raman spectroscopy and atomic force microscopy characterize untreated and treated E-3D sensor surfaces. The optimal treatment and activation methodology was applied to the electroanalysis of paracetamol (PAR) and caffeine (CAF) simultaneously using CV and differential pulse anodic stripping voltammetry (DPASV). DPASV measurements reveal limits of detection of 0.44 and 0.58 μmol L^-1 in a 0.5 mol L^-1 H₂SO₄ medium for PAR and CAF, respectively, with the treated and activated E-3D sensor. The principal achievement of this work was emphasizing the critical role of surface treatment and activation in enhancing the performance of the developed electrodes, thereby advancing technological applications of 3D-printed electrochemical sensors.

Quality parameters, physical-chemical characteristics, and antioxidant capacity are important to ensure the successful commercialization of honey. On the other hand, the presence of antioxidants in foods gives them greater added value. Thus, based on the study of total antioxidant capacity (TAC), along with the analysis of total phenolic compounds (TPC) and total flavonoid compounds (TFC), it is possible to classify honey according to its composition. First, all the samples were evaluated according to their polinic origin (melissopalynological analysis). The TAC was determined using both spectrophotometric methods (ferric reducing antioxidant power, FRAP) and electrochemical methods (ceric reducing antioxidant capacity, CRAC). All types of honey exhibited significant values for TAC, TPC, and TFC. To assess honey quality, methodologies such as moisture content, diastase activity, hydroxymethylfurfural (HMF), total acidity (TA), and water activity (A _w) were employed. Among the analyzed samples, 5 and 2 honey showed high levels of moisture (20.10-20.87%), TA (65.12-65.49 mequiv kg^-1), and HMF (>60 mg kg^-1), surpassing the limits set by Brazilian legislation. This indicates a potentially longer shelf life or the possibility of adulteration. Furthermore, it was concluded that the color of honey may interfere with FRAP (r = 0.837). In this regard, the CRAC assay presents a new alternative for evaluating TAC in bee products.