Research and preparation of γ-hydroxybutyric acid imprinted electrochemical sensor

Gamma-hydroxybutyric acid (GHB) is a potent central nervous system depressant, often used by criminals as a “date rape drug”, and is classified as a first-class controlled psychotropic drug in China. In view of the shortcomings of the existing detection methods (such as complex pretreatment required by chromatography-mass spectrometry, low sensitivity of chemical colorimetry, and weak signal of direct electrochemistry), this study prepared an imprinted membrane (MIM) by using o-phenylenediamine (o-PD) as the functional monomer and GHB as the template molecule through electro-polymerization. An innovative imprinted electrochemical sensor: GHB-MIM/GCE was constructed by combining molecular imprinting technology (MIT) and electrochemical technology. And potassium ferricyanide was used as the probe to achieve highly sensitive and selective indirect detection of GHB in aqueous solution. This sensor has excellent analytical performance: the detection limit is as low as 1.0×10⁻¹⁵ mol/L, and the linear range is as wide as 5.0×10⁻¹⁴ to 1×10⁻⁸ mol/L, significantly superior to existing methods. In addition, the sensor shows good reproducibility (RSD = 5.2%, n = 5) and stability (the response remains above 88% after 20 cycles of use). This study provides a new strategy for the on-site rapid and trace detection of GHB and expands the application of molecularly imprinted electrochemical sensors in drug analysis.