Banca de QUALIFICAÇÃO: BEATRIZ DO NASCIMENTO OLIVEIRA

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
STUDENT : BEATRIZ DO NASCIMENTO OLIVEIRA
DATE: 30/03/2026
TIME: 09:00
LOCAL: Google Meet
TITLE:

Development of technologies for the detection of acid phosphatase in biological samples

KEY WORDS:

Enzymatic biomarkers; semen identification; colorimetric sensing; on-site forensic testing; PAD;

PAGES: 40
BIG AREA: Ciências Exatas e da Terra
AREA: Química
SUMMARY:

In forensic science, the detection and evaluation of biological markers are essential for crime elucidation. In
this context, the enzyme acid phosphatase (AP) stands out as an important marker present in seminal fluid
samples. This work describes the development of a colorimetric method for AP detection, using ascorbic acid
2-phosphate (AAP) as a substrate. In the presence of the enzyme, ascorbic acid is hydrolyzed at pH 5.0,
releasing inorganic phosphate and reduced ascorbic acid (AAr), which is used as the indicator species. The
first step consisted of using the nitroso-R salt reagent (1-nitroso-2-hydroxynaphthalene-3,6-disodium
disulfonate, NRS) (λmax = 710 nm), which provides greater precision in colorimetric detection by minimizing
potential interferences caused by the natural coloration of the samples. The use of the NRS reagent stands out
for being simple, low-cost, stable, and widely available. The method demonstrated improved analytical
performance for AP detection in a linear range of 0.25 to 3.0 U L⁻¹, with a limit of detection (LOD) of 0.08
U L⁻¹. Meanwhile, the second stage utilized a paper-based analytical device (PAD), allowing for color
intensity monitoring with a 0.5 μL sample volume, with a linear range of 2.5 to 25 U L⁻¹ and an LOD of 0.83
U L⁻¹. Thus, the proposed procedures enabled rapid and selective qualitative and quantitative analyses,
applicable in the field or laboratory, reducing the possibility of false-positive results.

COMMITTEE MEMBERS:
Externo(a) à Instituição - JOÃO FLÁVIO DA SILVEIRA PETRUCI - UFU
Externo(a) à Instituição - ALINE THAÍS BRUNI - USP
Interno(a) - 1997465 - DANIELA SANTOS ANUNCIACAO
Interno(a) - 1904678 - JANAINA HEBERLE BORTOLUZZI
Presidente - 1613338 - JOSUE CARINHANHA CALDAS SANTOS