Laser-scribed graphene on polyetherimide substrate: an electrochemical sensor platform for forensic determination of xylazine in urine and beverage samples

• Published in: Mikrochimica acta (1966) 2022-12, Vol.189 (12), p.465-465, Article 465
• Main Authors: de Lima, Lucas F., de Araujo, William R.
• Format: Article
• Language: English
• Subjects: Analytical Chemistry; Beverages; Characterization and Evaluation of Materials; Chemical sensors; Chemistry; Chemistry and Materials Science; Electric properties; Electrochemical analysis; Electrochemical impedance spectroscopy; Electrochemical Techniques - methods; Fourier transforms; Graphene; Graphite; Graphite - chemistry; Infrared spectroscopy; Lasers; Microengineering; Nanochemistry; Nanotechnology; Original Paper; Polyetherimide; Polyetherimides; Raman spectroscopy; Sensors; Sex crimes; Sexual abuse; Spectrum analysis; Square waves; Substrates; Voltammetry; Wettability; Xylazine
• ISSN: 0026-3672; 1436-5073
• DOI: 10.1007/s00604-022-05566-1

A laser-scribed graphene (LSG) device fabricated on polymeric polyetherimide (PEI) substrate is reported for sensitive electrochemical detection of xylazine (XLZ), a veterinary drug that has been associated with drug-facilitated crimes. Morphological characterization was made by scanning electron microscopy (SEM), demonstrating that the electrochemical device presents a highly porous carbonaceous structure. In addition, Raman spectroscopy, Fourier-transform infrared spectroscopy (FTIR), wettability, electrochemical impedance spectroscopy (EIS), and cyclic voltammetry (CV) measurements were used to characterize the PEI-LSG material, which showed superior electroanalytical performance after a simple anodic treatment in an alkaline medium (applying 2 V for 120 s in 0.1 mol L −1 NaOH solution). The electrochemical determination of XLZ was carried out using square wave voltammetry (SWV), which showed sensitivity and coefficient of determination ( R 2 ) equal to 0.206 ± 0.008 A L mol −1  cm −2 and 0.991, respectively. In addition, we obtained a low limit of detection (LOD) of 1.39 × 10 −7  mol L −1 with a linear response in the concentration range 5.0 to 200.0 × 10 −6  mol L −1 . The PEI-LSG electrochemical sensor was applied to XLZ detection in commercial beverage and synthetic urine samples, providing recoveries between 96.0 and 114.8%. Collectively, our electrochemical sensor presents an easy method to manufacture reproducible (relative standard deviation (RSD) of 2.56%), low-cost ($0.12), and single-use (disposable) devices, which is a promising way for in-field determination of drug-facilitated sexual assaults and other relevant applications. Graphical Abstract