Forensic electrochemistry on a drop: bromocresol green-modified screen-printed platforms for dual colorimetric-electrochemical detection of scopolamine.
5 affiliations
- 1Faculty of Science and Engineering, Manchester Metropolitan University Dalton Building, Chester Street M1 5GD UK [email protected].
- 2Department of Chemistry, Federal University of Vales Do Jequitinhonha and Mucuri Campus JK 39100-000 Diamantina Minas Gerais Brazil.
- 3Institute of Chemistry, Federal University of Goiás Campus Samambaia 74690-900 Goiânia Goiás Brazil.
- 4Institute of Chemistry, Federal University of Uberlândia 38400-902 Uberlândia Minas Gerais Brazil.
- 5Department of Pharmacy, Federal University of Vales Do Jequitinhonha and Mucuri Campus JK 39100000 Diamantina Minas Gerais Brazil [email protected].
Abstract
A novel bulk-modified screen-printed electrode (SPE) was developed by incorporating bromocresol green (BG) as a pH-responsive colorimetric reagent, directly into the graphite ink formulation to create an integrated dual-response sensing platform. This bulk modification strategy enables complementary electrochemical and colorimetric responses on a single disposable device (BG-SPE), eliminating the need for additional reagents or multi-step procedures. The platform was applied to the detection of scopolamine, a clinically relevant tropane alkaloid associated with both therapeutic use and drug-facilitated criminal activity. The BG-SPE sensor enabled rapid, portable preliminary visual screening followed by electrochemical confirmation and quantification of scopolamine in beverages and biological matrices. Differential pulse voltammetry provided a wide linear range from 5 to 80 µg mL⁻¹, with limits of detection (3σ) and quantification (10σ) of 0.02 and 0.07 µg mL⁻¹, respectively, alongside excellent repeatability (RSD < 7.0% for peak current and <2.0% for peak potential). Method validation in real beverage samples (whiskey) and synthetic biological fluids (saliva, urine, and vitreous humour) yielded recoveries close to 100% with negligible matrix effects. The bulk incorporation of BG into the ink formulation provided reproducible electrode fabrication, supporting the use of bulk-modified SPE for on-site forensic screening, while allowing both analytical responses to be generated from the same sensing interface. The bulk-modified SPE integrates visual screening and electrochemical confirmation and quantification within a single portable sensing platform, enabling complementary analytical information to be obtained from the same sensing interface without requiring addition reagents.
Related
- Immersion-Controlled Nanoparticle Electrodeposition on a Patterned Pyrolyzed Photoresist Film Electrode for Single-Entity Electrochemistry Studies Using Scanning Electrochemical Cell Microscopy.
- Laser-Induced Graphene Paper-Based Microfluidic Platform for Dual-Mode Electrochemical and Colorimetric Detection of Glucose
- Ultra-dispersed metal oxide nanoparticles on graphitic carbon nitride as functional platforms for electrochemical nitrate valorization
- Surfactant-free electrochemical synthesis of layered Ag/Au bimetallic nanostructures as SERS platforms with DFT insights into their interfacial charge transfer mechanism.
- Poly(bromocresol green) modified screen-printed carbon electrode for selective voltametric detection of uric acid.
BibTeX
@article{melo2026forensic,
title = {{Forensic electrochemistry on a drop: bromocresol green-modified screen-printed platforms for dual colorimetric-electrochemical detection of scopolamine.}},
author = {Larissa M A Melo and Robert D Crapnell and Elena Bernalte and Daniel S Paula and Rodrigo A A Munoz and Wendell K T Coltro and Wallans T P Dos Santos and Craig E Banks},
journal = {RSC advances},
year = {2026},
month = oct,
doi = {10.1039/d6ra07984a},
url = {https://europepmc.org/article/MED/42840688},
note = {CC BY},
}
RIS
TY - JOUR
TI - Forensic electrochemistry on a drop: bromocresol green-modified screen-printed platforms for dual colorimetric-electrochemical detection of scopolamine.
AU - Larissa M A Melo
AU - Robert D Crapnell
AU - Elena Bernalte
AU - Daniel S Paula
AU - Rodrigo A A Munoz
AU - Wendell K T Coltro
AU - Wallans T P Dos Santos
AU - Craig E Banks
PY - 2026
DA - 2026/10/06
JO - RSC advances
DO - 10.1039/d6ra07984a
UR - https://europepmc.org/article/MED/42840688
AB - A novel bulk-modified screen-printed electrode (SPE) was developed by incorporating bromocresol green (BG) as a pH-responsive colorimetric reagent, directly into the graphite ink formulation to create an integrated dual-response sensing platform. This bulk modification strategy enables complementary electrochemical and colorimetric responses on a single disposable device (BG-SPE), eliminating the need for additional reagents or multi-step procedures. The platform was applied to the detection of scopolamine, a clinically relevant tropane alkaloid associated with both therapeutic use and drug-facilitated criminal activity. The BG-SPE sensor enabled rapid, portable preliminary visual screening followed by electrochemical confirmation and quantification of scopolamine in beverages and biological matrices. Differential pulse voltammetry provided a wide linear range from 5 to 80 µg mL⁻¹, with limits of detection (3σ) and quantification (10σ) of 0.02 and 0.07 µg mL⁻¹, respectively, alongside excellent repeatability (RSD < 7.0% for peak current and <2.0% for peak potential). Method validation in real beverage samples (whiskey) and synthetic biological fluids (saliva, urine, and vitreous humour) yielded recoveries close to 100% with negligible matrix effects. The bulk incorporation of BG into the ink formulation provided reproducible electrode fabrication, supporting the use of bulk-modified SPE for on-site forensic screening, while allowing both analytical responses to be generated from the same sensing interface. The bulk-modified SPE integrates visual screening and electrochemical confirmation and quantification within a single portable sensing platform, enabling complementary analytical information to be obtained from the same sensing interface without requiring addition reagents.
SN - 2046-2069
ER -