João Marcos Madurro - Academia.edu (original) (raw)

Papers by João Marcos Madurro

Revista Brasileira de Ciência, Tecnologia e Inovação

This study describe the development of an electrochemical immunosensor with a transducer platform... more This study describe the development of an electrochemical immunosensor with a transducer platform functionalized with the poly-(3- hydroxybenzoic acid), to detection of antibodies against the surface protein (Am1) of Anaplasma marginale. This biological probe was immobilized on the polymer under graphite and characterized electrochemically. The detections of antigen-antibody interactions were conducted using the signal obtained from the oxidation of 4-aminoantipyrine (4 -AAP), interleaved with Am1, to enable the use of voltammetry technique of differential pulse. The detections of antibodies of A. marginale, using the graphite electrode functionalized with the probe Am1 was 66% higher than the graphite electrode not functionalized. The time of storage of the immunosensor was satisfactory, with reduced peak current by 35%, after 90 days. The results demonstrate the excellent applicability of this new functionalized platform for probe immobilization and diagnosis of anaplasmosis witho...

Bioelectrochemistry, Aug 1, 2021

Alicyclobacillus acidoterrestris is an acidophilic and thermophilic bacterium present in the soil... more Alicyclobacillus acidoterrestris is an acidophilic and thermophilic bacterium present in the soil, often associated with the spoilage of acidic juices, such as orange juice. Their spores resist pasteurization and, when reactivated, modify the organoleptic properties of the juice, making it unsuitable for consumption, due mainly to production of guaiacol. Biosensors are detection devices that respond quickly and are easy to handle, with great potential for use in the juice production chain. In this context, this work reports an electrochemical genosensor for detection of A. acidoterrestris, based on a graphite electrode modified with electrochemically reduced graphene oxide, a polymer derived from 3-hydroxybenzoic acid and a specific DNA probe sequence complementary with the genomic DNA of A. acidoterrestris. Detection of the target was performed by monitoring the oxidation peak of the Hoechst 33258, a common DNA stainer. The genosensor detection limit was 12 ng mL-1 and it kept 77% of response after ten weeks, and a test showed that orange juice does not interfere with bacteria lysate detection. This biosensor is the first platform for electrochemical detection of the genomic DNA of A. acidoterrestris in the literature, and the first to use Hoechst 33258 as indicator with whole genomic DNA molecules.

Journal of Pharmaceutical and Biomedical Analysis, Oct 1, 2019

Highlights • Electrochemical immunosensor based in peptide predicted in silico for detecting anti... more Highlights • Electrochemical immunosensor based in peptide predicted in silico for detecting anti-T. gondii immunoglobulins; • Indirect ELISA confirmed T. gondii infection and peptide specificity; • The immunosensor discriminated serum samples from infected and uninfected mice; • The immunosensor discriminated different periods of infection in serum samples of infected mice.

Journal of Molecular Structure, Dec 1, 2008

This work reports theoretical and experimental studies on the first hyperpolarizability (β) of am... more This work reports theoretical and experimental studies on the first hyperpolarizability (β) of aminophenols, evaluating the influence of the NH2 group position relative to the OH group on the hyperpolarizability. A new extension of hyper-Rayleigh scattering technique using picosecond pulse trains was employed to obtain the experimental absolute values of (β). The theoretical static β(0) values were calculated using AM1

Electroanalysis, May 22, 2019

This work describes an electrochemical genosensor for detection of genomic RNA of Zika virus in r... more This work describes an electrochemical genosensor for detection of genomic RNA of Zika virus in real samples of infected patients, using a new platform based on graphite electrodes modified with electrochemically reduced graphene oxide and polytyramine-conducting polymer. The developed genosensor was suitable for differentiation between samples of healthy and infected patients with Zika virus by differential pulse voltammetry, detecting up to 0.1 fg/mL (1.72 copies/mL), showing good stability (about 60 days), rapid analysis (about 20 min) and potential for filling the lack of practical diagnostic methods for Zika virus.

Biosensors and Bioelectronics, Feb 1, 2018

Juvenile idiopathic arthritis (JIA) is a wide group of diseases, characterized by synovial inflam... more Juvenile idiopathic arthritis (JIA) is a wide group of diseases, characterized by synovial inflammation and joint tissue damage. Due to the delay in the implementation of biomarkers into clinical practice and the association with severe sequels, there is an imperative need for new JIA diagnosis strategies. Electrochemical biosensors based on screen-printed electrodes and peptides are promising alternatives for molecular diagnosis. In this work, a novel biosensor for detecting juvenile idiopathic arthritis (JIA) was developed based on the immobilization of the PRF+1 mimetic peptide, as recognition biological element, on the surface of screen-printed carbon electrode. This biosensor was able to discriminate the JIA positive and negative serum samples from different individuals using differential pulse voltammetry, presenting limits of detection and quantification in diluted samples of 1:784 (v/v) and 1:235 (v/v), respectively. Evaluation by electrochemical impedance spectroscopy showed R CT 3 times higher for JIA positive sample than for a pool of human serum samples from healthy individuals. Surface analysis of the biosensor by atomic force microscopy, after contact with JIA positive serum, presented great globular clusters irregularly distributed. The long-term stability of the biosensor was evaluated, remaining functional for over 40 days of storage (after storage at 8°C). Therefore, a simple, miniaturized and selective biosensor was developed, being the first one based on mimetic peptide and screen-printed carbon electrode, aiming at the diagnosis of the juvenile idiopathic arthritis in real serum samples.

Biosensors and Bioelectronics, 2022

With the increased demand for beef in emerging markets, the development of quality-control diagno... more With the increased demand for beef in emerging markets, the development of quality-control diagnostics that are fast, cheap and easy to handle is essential. Especially where beef must be free from pork residues, due to religious, cultural or allergic reasons, the availability of such diagnostic tools is crucial. In this work, we report a label-free impedimetric genosensor for the sensitive detection of pork residues in meat, by leveraging the biosensing capabilities of graphene acid - a densely and selectively functionalized graphene derivative. A single stranded DNA probe, specific for the pork mitochondrial genome, was immobilized onto carbon screen-printed electrodes modified with graphene acid. It was demonstrated that graphene acid improved the charge transport properties of the electrode, following a simple and rapid electrode modification and detection protocol. Using non-faradaic electrochemical impedance spectroscopy, which does not require any electrochemical indicators or redox pairs, the detection of pork residues in beef was achieved in less than 45 min (including sample preparation), with a limit of detection of 9% w/w pork content in beef samples. Importantly, the sample did not need to be purified or amplified, and the biosensor retained its performance properties unchanged for at least 4 weeks. This set of features places the present pork DNA sensor among the most attractive for further development and commercialization. Furthermore, it paves the way for the development of sensitive and selective point-of-need sensing devices for label-free, fast, simple and reliable monitoring of meat purity.

Journal of Electroanalytical Chemistry, 2019

This work describes the development of a genosensor for the detection of the hepatitis C virus (H... more This work describes the development of a genosensor for the detection of the hepatitis C virus (HCV) in real samples. Gold electrodes were modified with graphene oxide functionalized with ethylenediamine (GO-ETD) for the immobilization of a HCV specific probe. HCV infected sera and viral genomic RNA were evaluated using differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS). EIS measurements showed an increase of about twice in charge transfer resistance values, after addition of HCV genomic RNA. In the DPV analyses, the genosensor was able to discriminate HCV positive serum samples from HCV negative serum, with a difference of 3 times between these samples. It was observed an inverse linear relationship between the values of the peak current of the ferrocyanide ion oxidation and the concentration of the samples. The detection limit was 1:483 (v/v) or 1.36 nmol•L −1 of RNA. The developed genosensor enables a selective and specific diagnosis of hepatitis C.

Polymer Engineering & Science, 2017

The Streptococcus pneumoniae detection plays an important role in the diagnosis and monitoring of... more The Streptococcus pneumoniae detection plays an important role in the diagnosis and monitoring of pneumococcal diseases. A genosensor based on graphite electrodes modified with polymer was developed for such detection. First, the poly(4‐aminophenol) film was electrochemically deposited on a graphite electrode. Afterward, an S. pneumoniae‐specific oligonucleotide (Strep1), isolated from conserved regions of the bacterial genome, was immobilized onto the modified electrode surface and used for the test with complementary target oligonucleotide (Strep2) or genomic DNA. The genosensor was evaluated using electrochemical techniques and atomic force microscopy. Poly(4‐aminophenol) film caused an increase in probe immobilization, monitoring the guanine oxidation peak. The detection limits obtained using differential pulse voltammetry and electrochemical spectroscopy impedance were 54 and 28 ng mL−1, respectively. The novel genosensor was efficient for the immobilization and detection of S....

Journal of Applied Electrochemistry, 2017

Journal of Applied Electrochemistry, 2015

In this work, three polymeric films derived from hydroxyphenylacetic acid isomers were electropol... more In this work, three polymeric films derived from hydroxyphenylacetic acid isomers were electropolymerized onto the surfaces of graphite electrodes through cyclic voltammetry. Analysis of electrochemical behaviors and electrical properties of the three polymeric films were investigated and their probably structures were explored by molecular modeling. The best functionalization strategy for the incorporation and retention of adenine and guanine nitrogenous bases was the poly(3-hydroxyphenylacetic acid). It was applied for the immobilization of a nucleotide probe specific to DNA of the bacteria Neisseria meningitidis operated in amperometric and impedimetric indirect modes. The simple protocol of electrochemical detection of DNA by the bioelectrode, developed in this work, could be further enhanced and applied in a low-cost and painless platform to diagnose human meningitis infection.

International Journal of Electrochemical Science

This paper reports a new bioelectrode for detection of alanine aminotransferase (ALT), a biomarke... more This paper reports a new bioelectrode for detection of alanine aminotransferase (ALT), a biomarker of hepatic disorders, using pyruvate oxidase immobilized onto graphite electrode modified with poly(4aminophenol) and 4-aminoantypirine as electrochemical indicator. Assays through cyclic voltammetry and morphological analysis by atomic force microscopy indicated that the enzyme was successfully incorporated onto the graphite electrode modified with poly(4-aminophenol). The biocatalytic process used on the bioelectrode to evaluate ALT by voltammetry was based on the fact that the target alanine aminotransferase, in presence of L-alanine and -ketoglutarate, produces pyruvate, which is a substrate for the enzyme pyruvate oxidase (PyO) incorporated onto the modified electrode. The H 2 O 2 produced from the reaction pyruvate/PyO oxidizes chemically 4-aminoantypirine (4-APP), leading to a decrease in oxidation current of this compound. This decrease is associated with the consumption of 4-APP by competitive chemical reaction with H 2 O 2 , decreasing the availability of 4-APP to oxidation in the electrode, showing that the 4-APP oxidized electrochemically is inversely proportional to the amount of ALT. The bioelectrode showed attractive characteristics such as short response time (about 200 s), low detection limit to ALT (2.68x10-5 U/L) and good stability after storage (97% of response after 30 days), indicating to be a promising approach for diagnosis of hepatic diseases.

Brazilian Archives of Biology and Technology, 2021

Nowadays, a prompt and reliable diagnosis is one of the most critical measures for leprosy contro... more Nowadays, a prompt and reliable diagnosis is one of the most critical measures for leprosy control. The current diagnostic is based on clinical exams by a health care professional, and it may not recognize early signs of the disease. Therefore, other leprosy diagnosis methods are needed that are sensitive, disease-specific, and easy to deliver to the end-user. This study describes the construction of an electrochemical DNA biosensor to detect PCR products of Mycobacterium leprae using methylene blue as an indicator of the hybridization. The capture probe was immobilized on the graphite electrode modified with poly(4-aminophenol). The electrode surface was morphologically characterized by atomic force microscopy. Linear voltammetry was used to monitor the concentration of methylene blue on the DNA biosensor, which indicated a limit detection of 1 x 10-10 mol/L. The biosensor showed selective when placed to hybridize with a non-complementary sequence. This study suggests that the electrochemical DNA biosensor developed is promising for detecting DNA of Mycobacterium leprae.

BMC Proceedings, Oct 1, 2014

Journal of Molecular Structure-theochem, Nov 1, 2009

Ortho-, meta-and para-aminophenols have been used as monomers to form different and versatile pol... more Ortho-, meta-and para-aminophenols have been used as monomers to form different and versatile polymers, for example to immobilize biological macromolecules in electrochemical biosensors. In this work, we present a quantum-mechanical study about these three monomers as a way to elucidate some of the pathways involved in the electropolymerization of such compounds. As observed, the formation of these polymers depends on monomer resonance structure. This was investigated from their electrostatic potential maps and sets of partial atomic charges for all possible structures that must occur in solution during the formation of the polymeric film. Radical-cation calculations and analysis based on the Natural Bond Orbital theory were also performed. The analysis of frontier orbital permitted to suggest that electropolymerization should involve the pairing between radical cations from protonated monomers (reaction in acid media) and their respective conjugated bases (neutral monomers present in equilibrium).

Electroanalysis, Sep 11, 2020

This work describes the construction of a genosensor based on a graphite electrode modified with ... more This work describes the construction of a genosensor based on a graphite electrode modified with an reduced graphene oxide/poly(3-hidroxybenzoic acid) nanocomposite with an specific DNA oligonucleotide for detection of cattle mitochondrial DNA, in order to certify beef purity. Electrochemical and morphological analyses indicate that the genosensor allows duplex formation with the DNA of pure sample of beef lysate. The genosensor was selective, identifying up to 1 % (w/w) of pork in beef samples, showing good reproducibility and stability within six weeks of storage, and can be reused four times, being a great tool for the evaluation of beef purity, with application in the meat production and marketing chain.

Microchemical Journal, Jul 1, 2017

This paper describes the development of an immunosensor for the c-reactive protein (CRP), based o... more This paper describes the development of an immunosensor for the c-reactive protein (CRP), based on both direct and indirect electrochemical detections. The anti-CRP probe was grafted to the platform sensitized with poly(3aminothiophenol) and the interaction of the CRP target with the immunosensor was carried either directly or indirectly, using 4-aminoantipyrine (4-APP) as indicator. The immunosensor presents a linear response in the range from 75 ng•mL −1 to 150 μg•mL −1 and detection limit of 7.24 μg•mL −1 (N = 3). The biosensor specificity, which was determined in the presence of non-specific target is also presented in this paper. Assays realized conducted with real samples indicate that the immunosensor discriminates the serum samples from healthy and sick patients with efficiency. In addition, through atomic force microscopy, it was possible to observe differences between the immunosensor surface in the absence or presence of the CRP target.

Journal of Molecular Catalysis A-chemical, Mar 1, 2000

Ž. Ž New modified electrodes ME were prepared in coating carbon electrodes with cerium poly allyl... more Ž. Ž New modified electrodes ME were prepared in coating carbon electrodes with cerium poly allyl ether p-benzene-. sulfonate that display reactivity for acetic aldehyde and benzylalcohol oxidation. Electrolysis of benzylalcohol gave benzaldehyde and benzoic acid. These electrodes have been proven to be very stable and resistant and they have the advantage to perform easily in function in the para position of the benzene ring that opens many possibilities for the use of ME of the ion exchange type.