Development of electrochemical and colorimetric sensors for application in forensic interest samples

Author(s)

William Reis de Araujo

• Document type: Doctoral Thesis
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Conjunto das Químicas (IQ e FCF) (CQ/DBDCQ)
• Defense date: 2016-06-07

Examining board members

Thiago Regis Longo Cesar da Paixão; Lucio Angnes; Wendell Karlos Tomazelli Coltro; Ivano Gebhardt Rolf Gutz; Hugo Barbosa Suffredini

• Advisor: Thiago Regis Longo Cesar da Paixão

Abstract

This thesis shows studies and efforts to the development of chemical sensors for different applications in the forensic field. Electroanalytical methods were developed for detection and quantification of some compounds (procaine, phenacetin, aminopyrine, acetaminophen, levamisole) commonly found in the drug of abuse adulteration process and cocaine, as well as, fundamental studies about the electrochemical behavior of these compounds. It was also employed electrochemical methods for quantification of hazardous compounds such as explosives (picric acid) and melamine. Analytical methods with electrochemical sensors included electrochemical modification of electrodic surfaces, molecularly imprinted polymers (MIP), and paper disposable electrochemical devices using different voltammetric and amperometric techniques, rotating disc electrode (RDE) and quartz crystal microbalance. In addition to the fabrication of paper disposable analytical devices with electrochemical detection, it was also used the colorimetric detection to quantify some of the major adulterants in cocaine seizure samples, such as procaine and phenacetin, as well as analysis and discrimination of explosive compounds (peroxy and nitro explosives) in these low cost portable platforms. All proposed methods were always developed aming at theses characteristics: ease, convenience, low cost and portability for analysis directly at the measurement site with minimal laboratory infrastructure. Finally, we presented some studies conducted during research internship abroad (University of California - San Diego (UCSD)) in the area of Wearable Sensors, which have been developed methods for micronutrient analysis in sweat (Zn) and a metabolite (Uric Acid) in saliva using sensors applied directly to the human body (AU)

• FAPESP's process: 11/19903-5 - Development of electroanalytical methods for detection/discrimination of drugs of abuse, its adulterants and explosives in forensic samples
• Grantee: William Reis de Araujo
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)