▎ 摘　　要

Tramadol (TRA) is a drug commonly used to alleviate severe pain. It is sometimes abused by teenagers, who mix it with beverages. A glassy carbon electrode (GCE) was modified with hierarchical graphene oxide nanoplatelets (H-GONPs) and proposed as an electrochemical sensor platform to detect TRA. The surface morphology of H-GONPs was compared with that of graphene oxide nanosheets (GONSs). Both materials were morphologically, chemically, and structurally characterized. The adsorption and determination of TRA at both electrodes were tested using electrical impedance spectroscopy, cyclic voltammetry, and adsorptive stripping voltammetry. The H-GONPs/GCE showed a faster charge transfer rate and larger active surface area. The anodic current response of TRA was three times higher at the H-GONPs/GCE than at the GONSs/GCE. In the optimal condition, the calibration curve of TRA demonstrated good linearity in two TRA concentration ranges. Electrode sensitivity was high (20.7 mu A.mu M-1.cm(2)), limit of detection low (0.015 mu M), and precision and anti-interference good. The developed sensor was applied to detect TRA in pharmaceutical samples and spiked beverage, saliva, and urine samples. Recoveries were between 92 +/- 4% and 102 +/- 2% with RSDs < 4.3%. The results showed the good potential of the developed sensor for TRA detection. (C) 2021 The Electrochemical Society ("ECS"). Published on behalf of ECS by IOP Publishing Limited.