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Regina de Oliveira T, Oliveira Leite TH, Miranda WN, Manuli ER, Leal F, Sabino E, Pott-Junior H, Melendez M, Faria RC. Molecular test for COVID-19 diagnosis based on a colorimetric genomagnetic assay. Anal Chim Acta 2023; 1257:341167. [PMID: 37062564 PMCID: PMC10066033 DOI: 10.1016/j.aca.2023.341167] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Revised: 03/10/2023] [Accepted: 03/30/2023] [Indexed: 04/03/2023]
Abstract
The world is in a long pandemic period caused by the SARS-CoV-2 virus and massive diagnostic tests to assist efforts to control the spread of the disease and also to avoid new coronavirus variants are still needed. Herein, we propose a simple and accurate saliva-based colorimetric test for the diagnosis of COVID-19. Magnetic beads (MBs) modified with a sequence of single-strand DNA (ssDNA) complementary to the N gene of the SARS-CoV-2 RNA were developed and used for magnetic capture and separation from a complex saliva sample. A second biotinylated ssDNA sequence was applied, and the colorimetric detection was carried out by adding streptavidin-horseradish peroxidase conjugate, H2O2, and tetramethylbenzidine (TMB) as chromogenic substrate. The test does not require viral RNA isolation, transcription, or amplification steps and can be performed at room temperature. The molecular assay test can be run using 96-well microplates, allowing the diagnosis of a large number of samples in 90 min. A simple support for magnets was designed and constructed using a 3D printer that allows the magnetic separations directly in the 96-well microplate. The colorimetric test showed an excellent ability to discriminate between healthy individuals and patients infected with SARS-CoV-2, with 92% and 100% of clinical sensitivity and specificity, respectively. This performance was similar to that achieved using the gold standard RT-PCR technique. The proposed genomagnetic assay offers an opportunity to greatly increase population testing, contribute to controlling the spread of the virus, and improve health equity in testing for COVID-19.
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Affiliation(s)
| | | | - Wyllian Neves Miranda
- Department of Chemistry, Federal University of São Carlos, São Carlos, SP, 13565-905, Brazil
| | - Erika Regina Manuli
- Municipal University of São Caetano do Sul, São Caetano do Sul, SP, 09521-160, Brazil
| | - Fábio Leal
- Municipal University of São Caetano do Sul, São Caetano do Sul, SP, 09521-160, Brazil
| | - Ester Sabino
- Institute of Tropical Medicine, University of São Paulo, São Paulo, SP, 05403-000, Brazil
| | - Henrique Pott-Junior
- Department of Medicine, Federal University of São Carlos, São Carlos, SP, 13565-905, Brazil
| | - Matias Melendez
- Cloning Solutions Ltda, Barretos, SP, 14780-459, Brazil; Molecular Carcinogenesis Program, National Cancer Institute, Rio de Janeiro, RJ, 20231-050, Brazil
| | - Ronaldo Censi Faria
- Department of Chemistry, Federal University of São Carlos, São Carlos, SP, 13565-905, Brazil.
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Lopes JMS, Reis JRT, Machado AEH, Leite THO, Batista AA, Acunha TV, Iglesias BA, Araujo PT, Barbosa Neto NM. Influence of the meso-substituents on the spectral features of free-base porphyrin. Spectrochim Acta A Mol Biomol Spectrosc 2020; 238:118389. [PMID: 32417643 DOI: 10.1016/j.saa.2020.118389] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Revised: 04/14/2020] [Accepted: 04/18/2020] [Indexed: 06/11/2023]
Abstract
The role of meso-substituents on the spectral features of free-base porphyrins is explored. Meso-tetra(4-pyridyl)porphyrin is compared with meso-tetra(2-thienyl)porphyrin and meso-tetra(pentafluorophenyl)porphyrin. Our results indicate that some of the asymmetric Q-bands in the free-base porphyrin tend to become symmetric relative to the adopted meso-substituent. The results show that the outlying perturbations lead the free-base quasi-degenerated Qx1, Qx2, Qy1, and Qy2 bands to be closer in energy. Combined, absorption, fluorescence and Raman spectroscopies endorse our conclusions showing that both the frequencies and the Huang-Rhys factors associated with every vibronic progression are noticeably affected by the investigated meso-substituents. Our results confirm that the B-band is also multi-featured in agreement with what is found for the Q-bands.
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Affiliation(s)
- J M S Lopes
- Institute of Natural Sciences, Graduate Program in Physics, Federal University of Pará, Belém, PA, Brazil.
| | - J R T Reis
- Institute of Natural Sciences, Graduate Program in Physics, Federal University of Pará, Belém, PA, Brazil
| | - A E H Machado
- Institute of Chemistry, Federal University of Uberlândia, Uberlândia, MG, Brazil; Federal University of Catalão, Av. Lamartine Pinto de Avelar, 1120, CEP 75704-020, Catalão, GO, Brazil
| | - T H O Leite
- Department of Chemistry, Federal University of São Carlos, São Carlos, SP, Brazil
| | - A A Batista
- Department of Chemistry, Federal University of São Carlos, São Carlos, SP, Brazil
| | - T V Acunha
- Bioinorganic and Porphyrinoid Materials Laboratory, Department of Chemistry, Federal University of Santa Maria, Santa Maria, RS, Brazil
| | - B A Iglesias
- Bioinorganic and Porphyrinoid Materials Laboratory, Department of Chemistry, Federal University of Santa Maria, Santa Maria, RS, Brazil
| | - P T Araujo
- Institute of Natural Sciences, Graduate Program in Physics, Federal University of Pará, Belém, PA, Brazil; Department of Physics and Astronomy, University of Alabama, Tuscaloosa, AL, United States.
| | - N M Barbosa Neto
- Institute of Natural Sciences, Graduate Program in Physics, Federal University of Pará, Belém, PA, Brazil.
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