Combined Colorimetric and Electrochemical Measurement Paper-Based Device for Chemometric Proof-of-Concept Analysis of Cocaine Samples

Author(s)

Ameku, Wilson A. ^[1] ; Goncalves, Josue M. ^[1] ; Ataide, Vanessa N. ^[1] ; Santos, Mauro S. Ferreira ^[1] ; Gutz, Ivano G. R. ^[1] ; Araki, Koiti ^[1] ; Paixao, Thiago R. L. C. ^{[1, 2]}

Affiliation

^[1] Univ Sao Paulo, Dept Quim Fundamental, Inst Quim, BR-05508000 Sao Paulo - Brazil

^[2] Inst Nacl Ciencia & Tecnol Bioanalit, BR-13084971 Campinas, SP - Brazil

• Document type: Journal article
• Source: ACS OMEGA; v. 6, n. 1, p. 594-605, JAN 12 2021.
• Web of Science Citations: 0

Abstract

Cocaine (COC) is one of the most widely consumed illegal drugs around the world. Street COC is commonly adulterated with pharmaceutical compounds that mimic or intensify the COC's sensory effect. Adulteration is performed to increase the profit of criminal organizations and each one has their own way of doing it. Therefore, determining the composition of seized COC samples (chemical profile) provides evidence for the police to track criminal organization networks and their activity patterns. Using filter paper as a substrate, we developed a multiple detection paper-based analytical device (PAD) that combines colorimetric and electrochemical measurements to discriminate COC samples according to adulterant's content. A regular graphite lead modified with a gold film made from Au leaf (graphite/Au) to improve electron transfer was used as a working electrode. Silver and Ag/AgCI were used as auxiliary and reference electrodes, respectively. The colorimetric device was patterned using a laser cutter and coupled to the electrochemical device using a double-sided tape, allowing simultaneous analysis to gather more analytical information about COC samples. Graphite/Au was characterized by scanning and transmission electron microscopies and electrochemical assays. The simultaneous colorimetric and electrochemical analyses combined to principal component analysis improved the analytical characterization of COC trial samples and provided a fast discrimination based on the assembled database. (AU)

• FAPESP's process: 17/10522-5 - Development of alternative methods for fabrication of electrochemical paper-based sensors
• Grantee: Thiago Regis Longo Cesar da Paixão
• Support Opportunities: Regular Research Grants
• FAPESP's process: 19/16491-0 - Rapid, onsite detection of toxic metals combining paper-based electrochemical sensors and fast-scan cyclic voltammetry
• Grantee: Thiago Regis Longo Cesar da Paixão
• Support Opportunities: Regular Research Grants
• FAPESP's process: 16/21070-5 - Vibrational spectroscopy with spatial resolution
• Grantee: Mauro Carlos Costa Ribeiro
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 18/08782-1 - Miniaturized and integrated chemical sensors: new fabrication platforms for biological, clinical and environmental applications
• Grantee: Mauro Bertotti
• Support Opportunities: Research Projects - Thematic Grants