Desenvolvimento de kit colorimétrico e fluorimétrico para identificação fosfatase ácida em fluidos biológicos provindos de crimes sexuais

Abstract

In recent years, sexual crimes have been increasing exponentially, mainly against women, with more than 250 thousand cases since 2017. In this way, the search for biological fluids at the crime scene can be crucial in the preliminary analysis, however, currently available methods prove to be impractical and not suitable for all realities, which takes time to solve these crimes. In order to contribute and help to change this reality, this work aims at the development of a colorimetric and fluorescent kit (dual response) for the identification of semen in biological fluids. Based on a phosphorylation reaction of resorufin (1) and azo (7) dyes using the agent diethyl chlorophosphate followed by the dealkylation of the ethyl groups using the agent iodine-TMSi, it aims at the synthesis of colorimetric and fluorescent probes that are sensitive to phosphatase acid present in semen. The detection mechanism was based on the enzymatic reaction of acid phosphatase with the probes, resulting in a color change and fluorescence emission after exposure to biological samples. The synthetic route used was effective for the synthesis of the proposed probes, with global yields of 28 and 33%, for probes 3 and 9, respectively. The first synthesized probe, derived from the resorufin dye, showed promising results in tests with the acid phosphatase enzyme, with a detection limit of up to 0.2 U L-1 , and can be used as a colorimetric probe (abs = 572 nm, pH 8) and fluorometric (em = 580 nm, pH 8), acting through an off-on mechanism in real semen samples. The innovations achieved in this project involve the development of a method for detecting acid phosphatase semen as a marker, exploring a system that will be portable and simple to handle, allowing the obtaining of reliable, fast, selective and safe results, which, can serve as additional evidence to assist in the elucidation of crimes of a sexual nature against women, children and adolescents.