Smartphone-assisted lateral flow nanosensor for the selective detection of GHB in urine

Autores de IIS La Fe

• Andy Hernández Montoto

  Autor

• Estela Climent Terol

  Autor

• Ramón Martínez Máñez

  Autor

Participantes ajenos a IIS La Fe

• Garrido, E
• Hernández-Sigüenza, G
• Mollá-Guerola, L
• López-Lima, R
• Ortiz-Gómez, E
• Montà-González, G
• Martí-Centelles, V
• Gaviña, P

Grupos

• Unidad Mixta de Investigación en Nanomedicina y Sensores

Abstract

We report a rapid test strip based on mesoporous silica nanoparticles functionalized with a specific GABA B receptor agonist to selectively detect ?-hydroxybutyric acid (GHB) in urine samples. The sensing mechanism involves rhodamine B-loaded MCM-41 silica nanoparticles whose pores are capped with a GABA-derived ligand (baclofen) acting as a gatekeeper via supramolecular interactions with the GABA B receptor protein. In the presence of GHB, competitive binding produces GABA B receptor protein displacement, leading to pore opening and fluorophore release, which is detected via fluorescence readout. The nanosensor demonstrated high sensitivity, with a limit of detection (LOD) of 168 µM in buffer solution and 41 µM in diluted urine. Selectivity assays showed highly specific sensor response over common drugs such as cocaine, morphine, MDMA, heroin, scopolamine, 1,4-butenediol (1,4-BD), ?-aminobutyric acid (GABA), and ?-butyrolactone (GBL). The sensing material was also incorporated into a lateral flow assay (LFA) platform with a smartphone-assisted fluorescence readout, providing a rapid, portable, and low-cost analysis of GHB. The resulting test strip exhibited high sensitivity, with a LOD of 0.28 µM in diluted urine, which is low enough to clearly distinguish between physiological endogenous GHB levels (~96 µM) and exogenous intake within only 1 min, a crucial requirement in forensic and clinical toxicology. This portable, cost-effective method holds strong potential for on-site forensic and clinical GHB screening. © 2026 The Author(s).

Copyright © 2026 The Author(s). Published by Elsevier B.V. All rights reserved.

Keywords

• Biosensing Techniques; Humans; Hydroxybutyrates; Limit of Detection; Nanoparticles; Receptors, GABA-B; Rhodamines; Silicon Dioxide; Smartphone; Substance Abuse Detection; Assays; Barium compounds; Body fluids; Cost benefit analysis; Cost effectiveness; Diagnosis; Drug delivery; Drug interactions; Forensic engineering; Mesoporous materials; Nanoparticles; Nanosensors; Rhodamine B; Screening; Silica; 4 hydroxybutyric acid; cocaine; diamorphine; morphine; rhodamine B; scopolamine; silica nanoparticle; 4 aminobutyric acid B receptor; 4-hydroxybutyric acid; hydroxybutyric acid; nanoparticle; rhodamine; silicon dioxide; GABAB receptor; High sensitivity; Hydroxybutyric acids; Lateral-flow assays; Mesoporous silica nanoparticles; Receptors proteins; Smart phones; Smartphone-based biosensor; Test strips; G-hydroxybutyric acid (GHB); Article; energy dispersive X ray spectroscopy; fluorescence intensity; high resolution transmission electron microscopy; lateral flow immunochromatography; limit of